A comparison of private and public pressurized irrigation systems in different parts of the Kermanshah province, west Iran

Numerous pressurized irrigation systems have been developed during the last decades resulting in improved irrigation quality and water distribution efficiency. However, operation, maintenance and management of pressurized irrigation systems require technical expertise and knowledge which makes it difficult for local farmers in developing country such as Iran. From 1990 onwards, numerous pressurized irrigation projects have been designed and implemented by state agencies in different parts of the Kermanshah province with a total area of 24,500 km2, west Iran. Unfortunately, researches on evaluation of success or failure of such projects under various operating conditions are scarce in literature and little efforts have been made to compare the water use efficiency in state-operated projects with those implemented by the private sector and mostly performed by local farmers through low interest loan from Iran’s Bank Keshavarzi, a national Iranian bank committed to develop national agriculture sector. For the purpose of this study, 124 randomly-selected irrigation patterns implemented in state-funded and private sector projects in different parts of Kermanshah province were evaluated during two year field investigations under a wide range of climatological conditions with a total area of 1800 ha. Field inspections and interviews with local owners of pressurized irrigation systems during this study showed that different factors should be taken into account in order to determine the success or failure of such projects including managerial practices, awareness of the benefits of pressurized irrigation systems by local farmers, shortage of water supplies, selection of suitable cropping patterns and, finally, operational and economic constrains. The results of investigations on selected projects also indicated that the higher water use efficiency in projects run by private sector in pressurized irrigation systems can be attributed to the establishment of water conservation facilities, improved soil management, appropriate cropping patterns, extension of new crop varieties and a continuous increase in the use of nitrogen and phosphorus fertilizers.