Water and nitrogen use efficiency for summer corn under condition of irrigation with sewage effluent

One of the most important advantages of irrigation with sewage effluent is that it can provide the abundant nutrients for crop growth. For investigating the water and nitrogen use efficiency when irrigation with sewage effluent, an experiment was conducted in field with silt loamy soil and the summer corn (TUNYU-1) was used as test crop. Three irrigation levels with large irrigation rate of 108 mm, moderate irrigation rate of 83 mm and small irrigation rate of 58.3 mm respectively were set, during the summer corn growing season 4 irrigations were applied. Two fertilizer levels with 1500 kg urea/hm² for high level and 500 kg urea/hm² for low level were used respectively. Only irrigation with sewage effluent treatments contained both fertilizer levels. All the treatments totally are 9. Results indicate that the influence of irrigation rate, fertilizer level and irrigation water on crop height, leaf area index and yield is small. The cumulative evapotrsanspiration increases with the increasing of irrigation rate, but on the other hand the water use efficiency(WUE) decreases with the increasing of irrigation, and WUE is independent of fertilizer level and irrigation water quality. Nitrogen uptake by summer corn of irrigation with well water is higher than that of irrigation with sewage effluent, but the nitrogen use efficiency(NUE) of irrigation with sewage effluent is higher than that of irrigation with well water, and NUE is independent of the fertilizer level and irrigation rate.