Water and nitrogen use efficiency for winter wheat under the condition of irrigation with treated sewage effluent

To investigate water and nitrogen use efficiency for winter wheat irrigation with treated sewage effluent, an experiment was conducted in Yongledian irrigation experimental station during the winter wheat growing season with silt loamy soil. Winter wheat (BEIJING8—8866) was used as test crop. There were three irrigation levels were used, high 125 mm, moderate 83 mm and low 42 mm. Three different treatments under each irrigation level were applied respectively. Two fertilizer application levels with 1000 kg urea+500 kg compound fertilizer (with 8% N, P and K respectively)per hectare for high level and 500 kg compound fertilizer per treatments for low level were used respectively. Only treatments irrigated with treated sewage effluent contained both fertilizer levels. Thus made total of 9 treatments. Results indicated that the influence of irrigation rate, fertilizer level and quality of irrigation water on crop height was small; both leaf area index and yield increased with increasing irrigation rate and amount of fertilizer applied. The cumulative evapotranspiration increased while water use efficiency (WUE) decreased with increasing irrigation rate, and WUE was independent of fertilizer level and the quality of irrigation water. Total nitrogen uptake by plant and nitrogen use efficiency (NUE) were independent of irrigation rate, fertilizer level and the quality of irrigation water.