According to decline in water resources availability and quality and also increases population growth, one of the most important strategic policies for food security is agricultural vertical development which can be achieved by improvement of water productivity. Deficit irrigation by employing alternate furrow irrigation is one of the methods of water management in the field that its application increases water productivity and yield per each irrigation water unit. This study was conducted to evaluate and simulate the alternate furrow irrigation for wheat using SIRMOD model. To reach these aim, some experimental data for Kerman Zenderooh agricultural and environmental research center during 2005-2007 were used. This research was based on randomized complete block statistical design with four treatments normal and alternate furrow irrigation method with two planting distances 50 and 60 cm (T50, T100, T60 and T120) in three replications. Evaluation results by model showed that efficiency of application, irrigation and distribution of water can be improved 2 times in alternate furrow method as compared to normal method. There were 4, 10, 27, 43 minutes difference between observed and computed data of water time advances in treatments T60, T120, T100 and T50, respectively. In total, observations showed that alternate furrow irrigation with a spacing of 60 cm (T120) is suitable for wheat, even in sandy loam soils. This increases the efficiency of application, irrigation and distribution.

External fluted feed rolls are commonly used in grain drills. The fluted feed roll meters a volume of seeds and does not singulate the seeds as do the precision planters; therefore, there will be inherent variation in the number of seeds delivered per unit of time. This research was conducted to investigate the effect of seed meter drive shaft and ground speeds and outlet positions in a grain drill on the variation in wheat seeding rate and seed flow evenness from various outlets in short time intervals using the Coefficient of variation (CV) and the nonUniformity Coefficient (NUC). In this study, a grain drill with straight fluted metering mechanisms was evaluated on a test rig. Two rotational speeds of 16 and 23 rpm and two speeds of 2.5 and 3.6 km h-1 were selected for the seed meter drive shaft and the movement of the test rig, respectively. The results showed that, for a given test rig speed, the seeding rate changed proportional to the seed meter drive shaft speed, whereas for a constant speed of seed meter drive shaft, the seeding rate decreased as the speed of the test rig increased. Also, the seeding rates from all outlets were not the same. Outputs of some of the outlets were autocorrelated, for which selecting 12 or 24 seed samples randomly out of 36 consecutive samples were not essentially non-autocorrelated. Increasing rotational speed of seed meter drive shaft significantly increased the Coefficient of Uniformity of all outlets. The seed breakage was significantly increased with the speed of seed meter drive shaft. The CV and NUC exhibited similar trends. It can, therefore, be concluded that in grain drill evaluation, either CV or NUC could be used as an index of seed flow non-Uniformity.

Water must be uniformly distributed over the whole farm field if a uniform growth of irrigated plants is desired. Therefore, achieving acceptable Uniformity using a center pivot irrigation system is of utmost importance. This may be achieved by using an appropriate model to fine - tune the system by adjusting pressure, nozzle diameter, lateral spacing, revolution velocity, etc. Currently, suitable simulation models for fine- tuning the sprinkler irrigation are available. These models are useful tools for predicting operation parameters such as Uniformity Coefficient for various combinations of operation pressure and different meteorological conditions. The ballistic principle is the most common theory used in modeling water distribution Uniformity in sprinkler irrigation systems. This principle and the necessary experimental and computational steps taken necessary for calibration and validation of the model for determination of sprinkler irrigation Uniformity are presented in this paper. Experimental set-up for the determination of Uniformity Coefficient (UC) for different wind speeds included two operation pressures and two brands of sprinklers. The experiments were conducted on a farm adjacent to the Yaniq Village in the East province of Azarbayjan. Practical implications of the results indicated that relatively high UC may be achieved by the proper adjustment of pressure, the nozzle diameter and correct spacing of sprinklers.

Several studies confirm the negative effects of non- uniform distribution of water on crop productivity and deep percolation. This means that some parts of the farm get more water than required on the other hand, other parts of the farm suffer from under- irrigation and water stress. In this research, the best fit functions for prediction of Uniformity Coefficient and Distribution Uniformity obtained using 20 randomly selected pressure conduit irrigated farms in Dehgolan plain (10 classic sprinkler systems and 10 wheel move systems). The measured Uniformity Coefficient and Distribution Uniformity were compared by fitting normal, uniform and beta distributions functions. The results show that normal distribution has the best fit line in predicting the Uniformity Coefficient and Distribution Uniformity in all the 5 settlements in the10 wheel move farms with spacing of 9, 12, 15, 18 and 21 meters as well as in the 10 farms with classic sprinkler systems,. In all of three cases, normal distribution functions have the most accuracy in prediction of Uniformity Coefficient and Distribution Uniformity. Also the accuracy increased in wheel move system with decreasing the space between two frequent settlements.

Uniformity Coefficient (Cu) is commonly measured through field experiments done on barren lands. This is while crop cover has a significant effect on the Cu Uniformity of water distribution during irrigation. In the present study, in order to evaluate the effect of wheat plant density on the Cu of water distribution, after analysis of the statistical data using SPSS14 software, logical relationship between the Cu at 3 different densities (160, 180 and 200 kg/ha.), various sprinkler arrangements and different heights of plants (30, 45 and 60) was presented. Results of the study showed that the Cu triangular arrangement (90.86) was, 3.4 percent higher than that of the rectangular arrangement (87.87). In turn, the Cu of the square arrangement (58.91) was 4.2% higher than that of the rectangular arrangement. It was also found that the increase non-linearly with height of the wheat plant.

Introduction: RF receives and transmits inhomogeneity is one of the most effective causes of image nonUniformity in MRI images and is considered as an important source of error in quantitative studies. one Part of this inhomogeneity is the characteristic of RF coils and another part of it, is due to the interaction of RF field with the body being imaged. Materials and methods: In this study, RF field inhomogeneity of a volume head coil is measured in human brain (in vivo) as well as in water and oil phantoms, using a simple method that has been proposed by this group. Results and discussion: The results showed that RF inhomogeneity n water phantom is more than its value in oil phantom, even more than its value in human brain In vivo conditions. Non-Uniformity of the pattern shows that in both Invivo and water phantom cases, standing wave effect is dominant under our experimental conditions, which may cause overestimations in real values of RF inhomogenity parameters and so image quality factors, therefore, it should be considered in designing MR phantoms.  

Reduction of water losses due to increase in the application Uniformity in sprinkler irrigation systems needs appropriate selection of the sprinklers spacing and arrangement. In the present study, to evaluate the impact of spacing and arrangement of sprinklers on Uniformity Coefficient (UC) of the irrigation system and to investigate the qualitative and quantitative changes of UC due to changes in the parameters of the area covered by the sprinkler and wind speed, the test of distribution pattern of a single sprinkler was performed. The test was conducted according to ISO 8026, ASAE S398.1and ISO 7749, 2 standards on three VYR 35, IRILINE 30, and RAINBIRD 40B sprinklers. In this study, the square shaped arrangement had the highest UC and lowest sensitivity to decreasing Coefficient of Uniformity with an average of 5.3% and 5.5 percent for the average increasing of 59.4% and 98.3 percent in the covered area and wind speed, respectively. The least sensitivity of the UC were obtained for the IRILINE sprinkler with the mean reduction values of 3.4% and 5.48 percent for the average increasing of 37% and 117.8 percent in the covered area and wind speed, respectively. Results showed that to achieve the desired Coefficient of Uniformity, the maximum sprinkler spacing should be considered as 40 percent of the nominal application diameter of the sprinkler with a square arrangement when wind speed exceeds 4 meters per second.

The Coefficient of water distribution Uniformity in sprinkler irrigation systems is one of the important indicators that are effective in evaluating their performance and only high values can justify the implementation of these systems. The purpose of this research is to use support vector machine (SVM) and gene expression programming (GEP) models to simulate the Coefficient of water distribution Uniformity in the farm-conditions of Malekan plain in the northwest of Iran, which is in the catchment area of the Urmia lake is experiencing severe water stress.Field tests were carried out on seven farms equipped with a classic stationary sprinkler irrigation system with a movable sprinkler (Komet 162, 163) with variables of sprinkler intervals on laterals and manifolds, operating pressure and wind speed, and distribution Uniformity Coefficient data were obtained. The values of the indicators (RMSE, MAE, R2) were obtained in the training and test steps, respectively (3.5087, 2.6827, 0.8634) and (1.1787, 0.9494, 0.9833) for GEP. The values of the evaluation indices (RMSE, MAE, R2) for the most optimal SVM model in the test and training steps were obtained (4.8917, 4.2704, 0.7884) and (2.6790, 2.4113, 0.9185) respectively. In the training step, the value of CU(DDR(max)) for GEP and SVM model was calculated as 7.0540 and 5.2925 respectively. The value of this index in the test step for these two models was 20.83 and 9.28 respectively. The comparison of the value of this index also showed that the GEP model is more accurate than the SVM model.

Study of the hydraulic and technical characteristics of emitters is one of the most important issues in trickle irrigation research. The researcher carried out her work with nine types of pressure compensating emitter with codes of A, B, C, D, E, F, G, M and N based on a trickle irrigation physical model. All experiments are based on ISO 9261 standard and IRISI 6775 standard of the Institute of Standards & Industrial Research of Iran. The obtained results are as follows: 1) According to the Manufacturing Coefficient of variation and difference between the actual and nominal flow rates, models B and F were rated as good, models A, C, E and G as medium, and models D, M and N were ranked as unacceptable.2) According to the EU, models B, C, F and G were ranked as excellent, models A, D and E as good and models M and N were rated as weak.3) According to the UC, all models except M and N were more than 70% and their flow rate variation have normal distribution 3) Considering all manufacturing quality standards and emission Uniformity of emitters, models B, C and F were nominated as the best emitters.

Tillage practices during several years will result in an unleveled soil surface on farms. At present, in most regions of Iran, land leveling operations on farms are performed by conventional levelers and this leveling method does not have high accuracy. In this study, for the first time in Ahwaz city in south west of Iran, Miskin laser leveler and conventional leveler (Deghat Kesht Shiraz Leveler) were compared from technical aspects. This study was conducted in agronomic year of 2008-2009 on a farm with soil texture of clay loam in Albaji village which is located 10 km north of Ahwaz in Khuzestan province. Measured factors were water consumption volume, leveling index (LI) and land leveling Uniformity Coefficient (LUC). Research in the field of land leveling methods needs plots with large area, because in large areas, the leveling accuracy of leveler machines can be measured and compared correctly. Thus, our experimental farm included 14 plots, each one hectare. Statistical method for analysis was T-Student with two treatments (leveling by laser and conventional levelers) and seven replications. Statistical analysis was done by SPSS software. Results of mean comparison indicated that there is a significant difference at 1% level between laser leveler and conventional leveler for water consumption volume. Laser leveler reduced irrigation time about 35% as compared with conventional leveler. Therefore, application of laser leveler decreased water consumption volume about 82 lit/s. Leveling index in laser leveler was closer to zero in comparison to conventional leveler. On the other hand, the value of this index for laser leveling was more acceptable and suitable than conventional leveling. Also, LUC value for laser leveling was closer to one in comparison with conventional leveling. Thus, LUC value of laser leveler was better and higher than conventional leveler. Generally, regarding the obtained results in this study, application of laser leveler instead of conventional leveler can be recommended for leveling agricultural lands in Ahwaz.