Effects of saline water on cucumber yields and irrigation water use efficiency under drip irrigation

The experiment was conducted to investigate mainly the effects of saline water (EC = 2.2~4.9 dS/m) on cucumber yield, irrigation quantity and irrigation water use efficiency (IWUE) under drip irrigation in North China Plain, when the soil matrix potential (SMP) at 0. 2 m depth immediately under drip emitter was controlled from -10 to -50 kPa. The experiment results indicated when irrigation water salinity (EC i ) was greater than 1.1 dS/m, cucumber yield decreased with the increasing of EC i . When the SMP at 0.2 m depth immediately under drip emitter was controlled between -25 and -35 kPa, cucumber showed the most resistant to salinity, and cucumber yield decreased about 3% for 1 dS/m increase of EC. When the treatment with a higher SMP (-10 kPa), the irrigation quantity was more, and the IWUE was lower; whereas the treatment with a lower SMP(-50 kPa), the irrigation quantity was less, and the IWUE was higher. As can be known from this study, in the semi-humid regions with annual precipitation about 600 mm where no enough fresh water is available for irrigation, 2.2~4.9 dS/m saline water can be used by drip irrigation to irrigate crops such as cucumber, the moderate salinity susceptible crop, after several proper agronomic practices and water management strategies are taken.