This survey was carried out in order to evaluate the classic SPRINKLER IRRIGATION systems that were executed in three different locations of GORGAN. Evaluation was done over two different fields with 3 IRRIGATIONs and in one field with 2 IRRIGATION over growing cycle of the plants. The results also revealed that there are a grat difference between application of SPRINKLER IRRIGATION methoods and what they were to be in another words it is not justifiable due to factors such as: lack of constant control and management, after application; lack of compatible of design with operation; lack of user's knowledge and information of the systems; amount of applied water does not match requirement of the plants; greater influence of business and marketing with respect to high quality design. The mean values of DU,Cu and AELQ for field 1 equal to 59.6, 69.7 and 50.5 percent, and field 2 equal to 70.3, 82 and 50.2 percent, and field 3 equal to 69.8, 67.9 and 45.6 percent, respectively.

Agricultural sector is the greatest user of water in Iran, and increase of the consumption efficiency is necessary by considering the limited water resources in the recent years. Hasanlu IRRIGATION and drainage networks as a part of a larger project of Naghdi plan is one of the country's largest projects in the field of development of pressurized IRRIGATION systems. Hasanlu network supplies water to the systems of SPRINKLERs, surface gravity IRRIGATION, and hydroflums based on the available pressure head at the relevant sites. In this research, geographic information systems were used as a framework for storing, management, processing, analyzing and visualization of spatial information of Hasanlo project phase 1 to evaluate water management of this plan. For this purpose, the coefficient of uniformity and distribution uniformity in SPRINKLER IRRIGATION calculation toolbox developed and added to GIS as an extension, to simulate and evaluate the single or multi riser uniformity tests. Also, the risers discharge and application pressure were recorded at the site during the operation of the project. Results indicated that the pressure of risers varied from 0. 5 to 3. 9 bar and average Christiansen’ s coefficient of uniformity (CU) was under 50% that indicated poor water management in the farm level. Also, the satisfaction of stakeholders was in medium level.

A two years’ field experiments was conducted to determine the cotton water need at Hashemabad cotton research Station. The Hashemabad Cotton Research Station is located in north of Iran at 36° 51' N latitude and 54° 16' E longitude at the south-east corner of Caspian Sea and its height from sea level is 13. 3 meters. That station has a Mediterranean climate with relatively mild winters and dry summers. In this project, five IRRIGATION treatments contains T1= 100%, T2= 75%, T3= 50%, T4= 25%, T5= 0% at three replications on Randomized complete bloke design using SPRINKLER IRRIGATION system were studied. By analysis of variance indicated that there was no significant difference between T1, T2 and T3, in terms of seed cotton yield. However, in term of numerically, the yield of T3 had 22 and 16 percent over T1 and T2, respectively. The relative water use efficiency of this treatment was over others. According to this research project, the recommended of cotton IRRIGATION water is 50 and 80 percent at wet and drought years respectively. The amount of cotton water needed in the humid region is 3200 and 4600 m3/ha at wet and drought years, respectively. Based on the results of this study, it seems necessary that reduce of the amount of cotton IRRIGATION requirement in northern of Iran.

This research was conducted at Torogh Agricultural Research Station in Khorasan-e Razavi province to determine the impact of IRRIGATION cutoff at different growth stages and percentage of water use on the yield and water use efficiency (WUE) of wheat cultivars using SPRINKLER IRRIGATION. The study was done from 2006-2008. The experimental design was a randomized complete block design with a strip split plot layout and three replications. The three vertical plots were for IRRIGATION (70%, 85%, 100% of plant requirement), the three horizontal plots were for IRRIGATION cutoff point (full IRRIGATION, IRRIGATION cutoff at stem elongation, cutoff at pollination) Three wheat cultivars (Alvand, Toos, Gaskozhen) were the subplots. The yield means at 70%, 85% and 100% water consumption were, respectively, 3182, 4639, and 4748 kg/ha. Water consumption of 85% and 100% fell into statistical group A. The highest value for WUE was 1.849 kg/m3 at 85%, followed 1/389 kg/m3 for 70%, and 1.618 kg/m3 for 100%. The IRRIGATION cutoff treatment showed significant differences (P£ 0.05) for grain yield and WUE. Full IRRIGATION showed the highest grain yield (4557 kg/ha) and IRRIGATION cutoff at stem elongation and cutoff at pollination actually decreased yield to 4195 and 3817 kg/ha, respectively. Full IRRIGATION and IRRIGATION cutoff at stem elongation fell into statistical group A. Cutoff at stem elongation had the highest WUE (1.778 kg/m3). Combined analysis showed that wheat cultivar had a significant effect on grain yield and WUE. Alvand cultivar had the highest yield (4447 kg/ha) and WUE (1.718 kg/m3). The results showed that, where water shortage was not an issue, full IRRIGATION produced the best results. In areas of water shortage, 85% IRRIGATION using the cutoff at stem elongation method is recommended for the best results in yield, water consumption and WUE.

Providing the sugar beet water requirement using new IRRIGATION methods such as SPRINKLER, drip and subsurface IRRIGATION methods is very important because of high water requirement and long growth period of sugar beet. The aims of this study were to study the effects of IRRIGATION methods on quantity and quality parameters of sugar beet and comparison of water consumption and water ues efficiency. The experiments (C.R.B.D.) were conducted in 2001 at Kamal-abad research station in Karaj with 3 replications. The treatments were: 1) SPRINKLER IRRIGATION at 30×72 plots, 2) furrow IRRIGATION at 4×82 m plots and 3) furrow IRRIGATION with cut-back at 4×82 m plots. Under SPRINKLER IRRIGATION method, the sugar beet water requirement was stimated using Penman-Monthith method. Furrow IRRIGATION was irrigated based on traditional farming. In furrow IRRIGATION with cut-back, the entrance discharge was decreased to 0.7-0.8 furrow IRRIGATION after completing advance phase. The results showed that sugar content, root impurities (K, Na, αN), white sugar content, exractability, mollasses sugar, shoot weight, root weight, sugar yield and white sugar yield parameters haven't significant difference (p<0.05) between the IRRIGATION systems. SPRINKLER IRRIGATION had better preference over furrow IRRIGATION because of 31% saving in water and 55% increase in water use efficiency on the basis of root weight. Use of cut-back in furrow IRRIGATION caused no significant difference in root weight and its water use efficiency compared to SPRINKLER IRRIGATION (p<0.05).

A computer model (SPRINKLERMod) was developed to simulate hydraulics of SPRINKLER IRRIGATION systems. The objective of this paper is to describe mathematical background of this model for simulating pressures and discharges of SPRINKLERs along the laterals. The model is capable of designing two types of laterals: laterals with fixed SPRINKLERs and laterals with portable SPRINKLERs. The model shows the simulation results in the forms of tables and graphs. Laterals with one or two diameters on uniform or non-uniform slopes can be designed. The model provides graphical presentation of percentage of SPRINKLER pressure variations for different lateral inside diameters. The Hazen- Williams equation was used for the calculation of friction losses. The required input parameters for lateral simulation are lateral type, desired SPRINKLER operating discharge and pressure head, spacing between SPRINKLERs, distance of first SPRINKLER from lateral inlet, number of SPRINKLERs operating on the lateral, riser height, Hazen- Williams's pipe friction coefficient and lateral longitudinal slope or field elevations at each of the SPRINKLERs on the lateral. Laterals are simulated such that average SPRINKLER pressures and discharges become equal to the values requested by the designer. Iterative procedures were implemented to simulate SPRINKLER pressures and discharges on laterals and the Newton- Raphson iterative method was used for calculating pressure of each of the SPRINKLERs on the laterals with portable SPRINKLERs. In order to evaluate the model, some example results of the model were compared with classical design results. Since there is no formula for the calculation of the required lateral inlet pressure in classical design of laterals with portable SPRINKLERs in the scientific references, a new formula was developed. Averages of absolute percentage of variations of lateral inlet pressures for laterals with fixed SPRINKLERs and with one or two-size diameters ranged from 0.3 to 0.7 percent, respectively. This value for laterals with portable SPRINKLERs was 0.1 percent.

In the water-limited areas, the great challenge of the agricultural sector is more production from less water that it can be achieved by increasing water productivity. A field study was conducted to compare various cultivars of wheat to water using line source SPRINKLER IRRIGATION at GORGAN Research Station in 2005-2006. The effect of variable water supply on yield and WUE of six wheat cultivars were determined. Four locations with distance from the laterals were monitored all of the IRRIGATIONs. Four IRRIGATION treatments (W1, W2, W3 and W4) were provided by the reduction of IRRIGATION water with distance from the line source. The experiment used a strip plot design to examine the effect of fixed IRRIGATION rates on six cultivars (C1=Tajan, C2=N-80-6, C3=N-80-7, C4=N-80-19, C5=N-81-18, C6=Desconcido) with four replications. Each IRRIGATION treatment of each strip was divided into six cultivars treatments, along the length of the laterals. Result indicated that the grain yield was affected by IRRIGATION treatment and genotypes. Due to suitable rainfall during the growing season, soil moisture depletion was high in deficit IRRIGATION treatment (W4) as compared to W1 treatment. Generally, the WUE was increased with decreasing applied water under supplementary IRRIGATION. The optimum amount of water to achieve maximum WUE was a range of 290 to 320 mm in the above-mentioned cultivars. The highest and the lowest WUE was related to C5 (1.48 kg m-3) and C1 (1.3 kg m-3) respectively. The optimum yield to achieve the highest WUE was found between 4100 kg ha-1 (in C1 cultivar) up to 4900 kg ha-1 (in C3 cultivar).

Proper estimation of crop water requirement is very important for water resource conservation in Iran. However, in most studies in Iran, the estimation of evapotranspiration is based on long-term weather data. However, use of simultaneous weather data of a non-agricultural weather station may underestimate or overestimate the crop water requirement. Therefore, it is essential for IRRIGATION specialist to be aware of the error of evapotranspiration calculated by long-term weather data. The objective of this study was to evaluate accuracy of evapotranspiration of reference crop using long-term weather data in comparison with simultaneous weather data in drip and SPRINKLER IRRIGATION. The period was designated to be from 1995 to 2009 in Isfahan weather station, Kabootarabad weather station and Shahid Beheshti airport weather station. The maximum value of n-RMSE using long-term weather data in comparison to simultaneous weather data were 24% for trickle IRRIGATION and 18% for SPRINKLER IRRIGATION management, 22% in spring, 20% in summer, 44% in fall and 56% in winter. According to results of this study, the application of long-term weather data in deficit IRRIGATION management is not recommended. On the other hand, due to sensitivity of trickle IRRIGATION to water stress, the application of long-term weather data for estimating of evapotranspiration in IRRIGATION scheduling is not recommended. Finally, application of automatic weather stations and simultaneous weather data for accurate IRRIGATION management particularly in deficit IRRIGATION management in critical situation of water shortage is recommended.