Assessment of implemented sprinkler irrigation systems in Golestan province.

Background and objectives: At present, the development of new irrigation systems is one of the most effective strategies for efficient use of water resources. In recent years, the area covered by pressurized irrigation systems has been a growing trend. If the quality of the implementation of these systems (technical, administrative, operation, management and equipment) are not given sufficient importance, motivating farmers to use these systems gradually decreased and thus their area covered will be reduced. The present study was conducted to evaluate some sprinkler irrigation systems (on 21 farms) in Golestan province in the years 2012 and 2013.
Materials and methods: In this study, infiltration rate, hydraulic characteristics of the systems (pressure and flow rate of sprinklers, efficiencies, and uniformity), irrigation scheduling and wind and evaporation losses were considered.
Results: The results showed that 38% of sprinkler irrigation systems in terms of distribution of uniformity (DU) and application efficiency of low quarter (AELQ) and 48% of systems in term of coefficient of uniformity (CU) were below the acceptable values. In 50 percent of the systems that were evaluated, their Application efficiency (Ea) was more than 65% and they were acceptable, but in 40 percent of the systems, the Ea was less than 40% and they was unacceptable. The results showed that 39% of the projects, the amount of water loss due to evaporation and wind were more than 20%, which is unacceptable for a sprinkler system. In most systems, it has been observed that the designer suggested an irrigation scheduling, type of sprinkler or sprinkler and lateral spacing, but operator and also farmer operates other program. Comparison of the measured soil infiltration rate and application rate of sprinklers indicated that there is not an appropriate match between the estimated values by the designer and measured in the field. Some of the design parameters such as cropping patterns, sprinkler type, sprinkler and lateral spacing and the pump were changed while the running. Normally, a change in any of the mentioned parameters influence on all the basics including the irrigation scheduling.
Conclusion: The most important problems in terms of management and operation of sprinkler irrigation systems were inadequate awareness of users of the system and irrigation scheduling. Teaching and principles of irrigation scheduling is required to good management and proper operation of sprinkler irrigation system, resulting in such cases authorities must take effective steps. In general, farmers tend to perform pressurized irrigation systems especially when they receive financial facilities. But to achieve objectives such as efficient use of water resources that can be realized with the implementation of sprinkler irrigation systems is still faced with serious challenges.