Effect of reclaimed water irrigation on growth and water use efficiency of maize and soybean

Under the same irrigation management, plant height, leaf area, dry-grain weight and water use efficiency (WUE) always differ due to differences in water quality. Pot experiment was conducted with fresh water(F) as the control treatment to compare the effect of reclaimed water Second-Grade S), Third-Grade (T), and Original-Sewage(O) from Beijing Gaobeidian sewage water treatment plant］irrigation on the growth and WUE of maize (Zea ays L.) and soybean (Phaseolus vulgaris L.). From the results, it is observed that S inhibits maize growth, while T promotes maize growth in the breeding stage. S and T reclaimed water irrigation shows a promotive effect in breeding and flowering stages, while no effect in the harvest stage of soybean. With regard WUE, a set of reclaimed water shows an inhibition effect in maize breeding stage, which gradually changed into a promotive effect after jointing stage. Another set of reclaimed water is observed to have a promotive effect in soybean breeding stage, which also gradually faded out after the flowering stage. In conclusion thus, third-grade reclaimed water (T) irrigation has beneficial effect on the growth and WUE of maize in all growth stages. Second-grade reclaimed water (S) irrigation inhibits growth and WUE of maize in breeding stage, but promotes growth and WUE after the jointing stage. The two grades of reclaimed water irrigation of soybean benefit all growth stages, and not remarkely influence WUE.