Factors affecting success and failure of trickle irrigation systems in Balochistan,Pakistan

An evaluation of performance of trickle irrigation systems installed in Balochistan, Pakistan during 1982–2002 was conducted by field surveys, physical verifications and interviews with farmers. Thirty systems were fully or partially operational and 76 had been abandoned. Successful systems required clean and reliable water supply, availability of spare components and accessories for replacements, skilled manpower, and a high level of interest and participation by the owner. The dominant species irrigated with these trickle systems were apples, grapes, and mixed orchards. Installations of trickle systems on old mature orchards were not generally successful due to lack of adaptation of the new system to limited and scheduled irrigation supplies. Many of the irrigators were not instructed on how to adjust the trickle system to meet changing needs of the plants. Consequently, growth of some of the trees was stunted and a few of them died. Lack of technical skill to repair and maintain the system and non-availability of replacement parts were general causes of failure of installed trickle irrigation systems. Clogging of the emitters was the primary specific cause of failure. Emitters with a larger opening that will not be clogged by most of the contaminants contained in the water available to these farmers and turbulent action screening systems to take out the other contaminants are proposed as solutions to this problem. Commercial shops, which sell the components, carry replacement parts and provide after-sales service are needed to keep trickle systems functioning in these isolated areas.