Effect of saline water on cucumber (Cucumis sativus L) yield and water use under drip irrigation in North China

Saline water has been Included as an important substitutable resource for fresh water in agricultural irrigation in many fresh water scarce regions In order to make good use of saline water for agricultural irrigation in North China a semi-humid area a 3-year field experiment was carried out to study the possibility of using saline water for supplement irrigation of cucumber Saline water was applied via mulched drip irrigation The average electrical conductivity of irrigation water (ECIw) was 1 1 22 29 3 5 and 4 2 dS/m in 2003 and 2004 and 11 2 2 3 5 42 and 49 dS/m in 2005 Throughout cucumber-growing season the soil matric potential at 02 m depth immediately under drip emitter was kept higher than -20 kPa and saline water was applied after cucumber seedling stage The experimental results revealed that cucumber fruit number per plant and yield decreased by 5 7% per unit increase in ECiw, The maximum yield loss was around 25% for ECiw of 4 9 dS/m compared with 1 1 dS/m Cucumber seasonal accumulative water use decreased linearly over the range of 1 5-69% per unit increase in ECiw As to the average root zone ECe (electical conductivity of saturated paste extract) cucumber yield and water use decreased by 108 and 103% for each unit of ECe increase in the root zone (within 40 cm away from emitter and 40 cm depths) respectively After 3 years irrigation with saline water there was no obvious tendency for ECe to increase in the soil profile of 0-90 cm depths So in North China or similar semi-humid area when there is no enough fresh water for irrigation saline water up to 4 9 dS/m can be used to irrigate field culture cucumbers at the expense of some yield loss (c) 2010 Published by Elsevier B V