Effect of drip irrigation with saline water on water use efficiency and quality of watermelons

High ground water salinity, high water table and secondary soil salinization are dominant in the Hetao Region, China. For the purposes of eliminating secondary salinity and enhancing water use efficiency, drip irrigation of watermelons with saline water was conducted in order to reduce ground water level and soil salinization. Saline groundwater, ranging in salinity from 3.3 dS m(-1) in the early season to 6.3 dS m(-1) at the harvest time was used. Four irrigation treatments ( control, 30, 60, and 90% of evaporation from Chinese Evaporation Pan) were used in the experiments. The control treatment was not irrigated through out the season, as is the local practice. The yield of watermelons was increased and the quality improved under drip irrigation, as compared with control, with the highest increases in both yield and quality in the 60% treatment. The water use efficiency as determined by lysimeter measurements for different treatments had the same trend. The water-product efficiency in the four treatments were 39.2, 30.7, 21.45, and 14.3 kg m(-3), respectively. Salts accumulated in the topsoil layer close to the emitter in the 30% treatment. Most salts were leached out of the root zone in the 60 and 90% treatments. The results suggested that drip irrigation of watermelon with saline water was feasible.