PANCHO-IRRIGATION SYSTEM - A WASTEFUL PRACTICE OF IRRIGATING RICE FIELDS IN THE LOWER INDUS BASIN OF PAKISTAN

In spite of water scarcity, farmers in the Lower Indus Basin of Pakistan are still using pancho-irrigation system, a system where standing water in the rice fields is drained after every 4-5 days and fresh canal water is applied to replace the drained water. Three systems: (i): pancho (ii) partial pancho that involves partial drainage of standing water occasionally and (iii) non-pancho where water is kept standing throughout the growing period, were tested and evaluated in selected fields. On an average, 408 mm (19%) and 785 mm (59%) excess gross water was applied under pancho irrigation as compared to partial pancho and non-pancho irrigation systems, respectively. The water drained out through rice fields under pancho and partialpancho irrigation systems was 559 mm and 362 mm, respectively. The net water applied in pancho irrigation was 226 mm and 211 mm higher when compared to partial and non-pancho irrigation systems, respectively. The water table was found to be raised from 1-3 m to 10-20 cm during the rice growing season. The average rice yield was 12-16% higher under nonpancho when compared with pancho and partial-pancho systems. The water productivity of rice under non-pancho irrigation was 17-24% higher as compared to pancho and partial pancho-irrigations systems. The results revealed that by avoiding pancho irrigation, about four billion cubic meters (BCM) water can be saved in one season without compromising the rice yield. Moreover, avoiding pancho irrigation can also help control water logging and salinity in the area.