جستجوی مقالات مرتبط با کلیدواژه « مدیریت آب کشاورزی » در نشریات گروه « کشاورزی »

This research assesses and investigates the impact of automating the Abshar irrigation network's main canal using a decentralized control system on the adequacy and stability of surface water distribution. To achieve this, the study analyzes 30 years of historical discharge data at the Abshar diversion dam and selects seven representative operational scenarios. It then employs the Integral-Delay (ID) hydraulic simulation model to simulate surface water distribution in the main canal under each scenario (a total of 540 simulations). These simulations are compared with results obtained using a simplified Integral-Delay (ID) mathematical model. Additionally, the research develops a decentralized PI automatic control system model for the network. This control system model is then integrated with the Integral-Delay (ID) hydraulic simulation model within the MATLAB environment. By utilizing system identification techniques, the study determines the proportional and integral gains for each controller in the control system. Finally, the performance of the automated control system is evaluated by analyzing the simulated surface water distribution results for the chosen scenarios using performance indices related to water distribution adequacy and stability. This allows for a comparison of the automated control system's effectiveness with the pre-automation scenario.

Irrigation network is a set of hydraulic channels and related structures that is created with the aim of transferring, distributing and delivering water fairly as well as efficiently. However, due to constraints resulting from type of management and maintenance, climate changes, social and cultural characteristics of users, and financial issues, their performance are usually faced with major challenges. Qazvin irrigation network is one of the modern networks in the country and after more than 40 years of implementation of this network, many problems and challenges in the field of agricultural water management are observed in this network. The purpose of the present research is to identify the important challenges in the field of agricultural water management in Qazvin plain irrigation network, to investigate the importance of challenges and performance in relation to the challenges, and finally to provide practical strategies to improve the state of the system with a new approach by using Importance-Performance Analysis technique. The method of conducting the study to identify the challenges has been library studies and then using Delphi technique. Furthermore, the importance of the challenges has been identified by using Best-Worst method. Evaluating the responce of the officials authorities  to the challenges using Importance-Performance Analysis technique, demonstrates that the challenges of lack of enough motivation in farmers to reduce agriculture water consumption, lack of governmental supports for established organizations, lack of supervision on implementation of crop patterns and cultivation area, budget issues, and lack of sufficient training for farmers, in ordre are five challenges in the first quadrant of the importance-performance matrix that should be prioritized for improvement. Several practical solutions to solve the challenges for Qazvin plain irrigation network such as doing more support from government in terms of using suitable irrigation methoed while considering the approved crop pattern and providing clear information for the statue of current situation and making coordination among all types of involved sectors are presented in the results section.

The present study was conducted to analyze wheat farmers’ behavior regarding water use and conservation in the Orzuiyeh County based on the theory of Social Cognition. The statistical population of the research was 1350 wheat farmers in the central district of the Orzuiyeh County that 135 of them were selected by using Bartlett et al. table of sample size. They were randomly selected. The data gathering tool was a researcher-made questionnaire based on social cognition theory whose face validity was confirmed by a panel of academic and performance experts. The reliability was also determined by conducting a study and calculating the Cronbach's alpha coefficients (0.58-0.86). The results of correlation analysis of the study variables showed that there is a positive and significant relationship between all the constructs of the theory (social structure factors, expectation of outcome, understanding of others behavior, self-efficacy and behavioral intention) and farmers' water management behavior. The results of multiple regression showed that the constructs of the theory predict a total of 36% of the variations of the management behavior of wheat farmers. In addition, the variables of understanding the behavior of others, self-efficacy and behavioral intention had significant influence on wheat farmers’ behavior of water use in the county. At the end, implications of the study for changing farmers’ behavior of water use are discussed.

A multi-objective linear optimization model has been formulated, which is used for water and crop area allocation in two irrigation and drainage networks of Dorudzan and Karbal, including five farming regions. The developed model is based on four bankruptcy rules of proportional cutback (PC), constrained equal awards (CEL), constrained equal losses (CEL), and adjusted proportional (APR) in terms of the certainty and uncertainty in the water availability. The developed model has four objective functions to reflect the various agricultural and environmental consumptions and is solved for two dry and non-dry conditions using a fuzzy compromise approach. The outputs of the model showed that the regions with higher shares of water receives the most allocated water through the bankruptcy rules of the PC and CEL in dry and non-dry condition, respectively. On the other hand, the most allocated water for the regions with lower shares of water occurs through the bankruptcy rule of the CEA in both hydro climatic conditions. The outcome of the stability evaluation using the bankruptcy stability index (BASI) indicated that this criterion could not be used to evaluate stability under all bankruptcy situations; thus, one should take the necessary precaution for making a decision according to its output

The lack of water and soil resources and their salinity are important points in the agricultural sector. Investigating the interactions between salinity and irrigation on plant yields is important in order to improve soil management and water use in arid and semi-arid regions. The purpose of this study was to study and evaluate the production functions of Basilicum L. in Mazandaran mass cultivar under simultaneous stress conditions of water and salinity. For this purpose, an experiment was conducted on a hectare research site in the Dushantepheh research center of Tehran. In this study, we used microplate weight-drainage to determine the rate of evaporation-transpiration of basil plant. Factorial experiment was conducted in a completely randomized design with four irrigation treatments including complete irrigation (FI), irrigation with 40 (DI40%), 60 (DI60%) and 80 (DI80%) water requirements of the plant and three subsoil treatments Irrigation water with a conductivity of 175/1 (S1), 3 (S2) and 5 dS / m (S3) for two consecutive years of 1395 and 1396 was carried out. The results showed that the basal plant yield reduction was 3.1 dS / m for irrigation water salinity and 10% for grazing line slope.

It is very important to estimate the actual water requirement of the plant for irrigation planning and hence effective water management in the field. The purpose of this study was to evaluate the conventional methods of estimating crop water demands and the actual water requirement of basil plant under field conditions. For this purpose, an experiment was carried out on three separate hectares, with three different methods of estimating basil water requirement, including the method of Standard Class A evaporation pan, the method of TethaProbe soil moisture set, and a proposed weighing micro-lysimeter method. Besides, the study compared four irrigation treatments including full irrigation (FI) and deficit irrigation at (DI 80%), (DI 60%), and (DI 40%) of water requirement for two consecutive years in 2017 and 2018. The results showed that the highest amount of basil evapotranspiration was measured at 11.2 mm/day, 53 days after planting. Also, basil crop coefficient values at the initial stages, development, middle, and end of growth were 0.63, 1.08, 1.12, and 0.97 respectively, and the highest basil coefficient in the 25th of July was equal to 1.26. The highest yield of fresh matter in the direct method of estimating water demand was obtained at 5998 and 5966 kg ha-1, respectively, in 2016 and 2017 in full irrigation. Also, the results of this study showed that the proposed lysimeter method improved the method of Class A pan and soil sampling by, respectively, 10% and 8% water consumption, and yields by 10% and 5%, respectively. Also, with this method, the maximum economic return was 4186 Rials per cubic meter of water.

This study has aimed to analyze the farmers’ skills on optimal use of agricultural water resources; since the skills are a reflection of knowledge, attitude, and facilities. The target population of this study was all farmers from Bahar County, Hamedan province (N=1931) that 271 of them were selected by random sampling according to Cochran formula. The data collection instrument was a questionnaire which its validity confirmed by a group of relevant experts and the reliability of the variables was calculated using ordinal alpha coefficient (α=0.85-0.93). There were significant differences between Knowledge and skills about optimal use of agricultural water resources of Farmers that participated in related training courses and those didn’t participate, according to the results of Mann-Whitney test. Also farmers categorized based on the land ownership, information resources and water supplies were significantly different in terms of their water management skills, according to the results of Kruskal-Wallis test. According to the results of Spearmans’ correlation tests, there were positive significant relationships between skills with variables of knowledge, attitude, and number of land plots; while this variable was negatively and significantly correlated with the amount of the annual production, total hectares of rainfed lands, and the amount of using chemical fertilizers. Moreover, based on the result of ordinal regression, 50.9% of the skills variations could be explained by three variables as the farmers' knowledge and attitude and number of land plots.

The main purpose of this study was to explore extension- training factors affecting the agricultural water management in Hamadan's potato production. This research has been done through a surveying method and data were gathered through a questionnaire tool. The study's population included 2341 potato farmers around Hamedan, which of those 330 samples were selected based on Cochran formula by a simple randomized sampling method. The content validity of the questionnaire was confirmed by a team of agricultural experts and professors in agricultural extension and education department of Bu-Ali Sina University. The reliability of the research instrument was determined using Ordinal theta coefficient (θ= 0/80-0/95). The results of the factor analysis showed that the factors affecting on agricultural water management can be classified in 6 groups. These were: the mass media factor, quality of extension services centers, experts' skills, local institutions and social networks, visit system, and training courses. These factors explained 70 percent of the total variance changes. Results from ordinal regression analysis indicated that knowledge, extension-training factors, and attitudes explained 25 percent of the probability of variance of agricultural water management variable.

Due to its biological nature and high dependence on regional condition, agriculture is the largest consumer of water resources in many countries. Hence, today, agricultural water management plays an important role in the use of water resources of these countries. The present study used Genetic Algorithm to optimize cultivation area, allocate irrigation water, and maximize profits gained from the cultivation of some crops under various weather conditions in Qazvin Plain (located in the north west of the central plateau of Iran), where some of the required water is obtained from Taleghan dam. In this study, different probability levels of rainfall, evaporation, and input flow of optimization were combined under four different weather conditions. The results showed that in normal, wet, dry, and hot - dry weather conditions, the profit earned from the new cultivation pattern introduced by the model was much more than that of the current pattern. Moreover, following this new pattern could mostly result in lower water consumption in this sector, such that the volume of water stored in the dam reservoir at the end of the operation in wet, normal, dry, and hot-dry conditions would increase by, respectively, 262045.2, 2862686.6, 273089 and 955542 m3. The results showed that the cultivation area of sugar beet in every of the four different condition was reduced (over 80%) because of its high water requirement and low yield, therefore, its cultivation is not recommended under any weather conditions in the studied area. Following the new cropping pattern delivered by this model, the farmers’ profit in wet, normal, dry, and hot-dry conditions would increase by, respectively, 2.81%, 2.62%, 1.34%, and 1.53% compared to the prevailing pattern.

Soil unsaturated zone is one of the important parts of hydrological cycle that has an especial role in agricultural water resources management. The objective of this research was to determine the amount of root water uptake under simultaneous water, salinity, and nitrogen stresses as prevailing conditions in arid and semi-arid regions. To do so, the experiment was conducted with four quantitative levels of irrigation water including 120, 100, 80, and 60 percent of crop water requirement, four qualitative levels of irrigation water including 1.2, 3, 5, and 8 dSm-1 and four nitrogen fertilizer levels including 100, 75, 50, and zero percent of fertility requirement. The results indicated that based on calculated statistics, the basil response was suitable simulated by MB-MB-EXP model under simultaneous triple water, salinity, and nitrogen stresses (nRMSE=7.22 and ME=19.05). The sensitivity analysis of the models indicated that MB-MB-VG model with the lowest input parameters and relatively low sensitivity to these parameters (Sc

The main purpose of the present study was to investigate personal and professional factors influencing farmer's perception towards problems of agricultural water management in Karaj County The Statistical Population of the study consisted of 5297 farmers in Karaj County out of which 142 farmers were selected as sample using Cochran Formula for determining the sample size and stratified proportionate random sampling technique for reaching the samples. A questionnaire was developed for gathering data and information. It was validated through getting the viewpoints of some faculty members of the Department of agricultural Extension and Education, University of Tehran as well as some staff experts of the Ministries of Jihade-Agriculture and Power. The reliability of the main scale of the questionnaire was approved by Cronbach Alpha Coefficient which was equal to 0.76 indicated the tool of study is reliable. The data were later analyzed by SPSS-win. The results indicated that there was significant and positive relationship between farmers perception towards problems of agricultural water management with their farming experience. In addition, the findings revealed that different groups of farmers classified based on grouping variable such as use of credit, water resources possession, educational level, farming systems, different technologies used for water exploitation were significantly different in terms of perception towards problems of agricultural water management. In addition farmers categorized based on variables such as farming systems and water transfer method were significantly different in terms of facing problems of agricultural water management as showed by Kruskal Wallis. According to an overall conclusion, four factors viz., education, credit, technology and farming system structure are highly influential on reducing problems of agricultural water management.

The purpose of the present study was to investigate and analyze the influence of water users’ cooperative (WUC) on farmers’ attitudes toward optimum agricultural water management practices with an approach to compare the two groups of farmers in irrigation networks with WUC and without it. The research method was a descriptive-correlational and causal-comparative study of the survey type. The target population in the study was the entire farmers of irrigation networks in Khorasan-Razavi Province. Using stratified random sampling technique, 335 participants were selected as a statistical. The content and face validity of the questionnaire was specified after several times of review and correction by the faculty members at Tarbiat Modarres University and the executive experts of Agricultural Jihad Organization and Regional Water Joint-stock Company in Khorasan-Razavi Province. The reliability analysis was conducted and Cronbach’s alpha values for the various sections of instrument were estimated to be between 0.73 and 0.86. The results of descriptive findings showed that attitude rate more than half of studied farmers (55.1%) regarding agricultural water management were at positive relatively and positive levels. Moreover, the results from statistical analyses indicated that WUC was very effective on the development of factors related to the social, human, physical, financial, and natural capitals, so that the WUC irrigation network with increases in the components of social confidence, solidarity, and participation, improved extension contacts, developed appropriate information channels, improved the status of regional irrigation system, and increased water users’ participation in irrigation water management were more effective on farmers’ attitudes toward the development and application of agricultural water management strategies such as under-pressure irrigation technology compared to non-WUC irrigation networks.