| Irrigation with industrial and domestic sewage has increasingly become popular in most areas of China where there is short of fresh water. Unlike fresh water, biogas liquid is rich in nitrogen and phosphorus but contains other contaminants too. Irrigation with such liquid will therefore arouse concerns over food and environmental safety. A field experiment was conducted to study the effects of irrigation rates and frequency of biogas liquid in combination of two rates of nitrogen fertilizer on growth, yield, grain quality, water use efficiency（WUE） of winter wheat. The growth index at shooting period, yield, grain starch of winter wheat were significantly higher under the sufficient irrigation（irrigation quota for 900 m3·hm-2） than under less-sufficient irrigation（irrigation quota for 600 m3·hm-2）. The differences between two treatments were 19% and 9% for yield and starch content, respectively. No significant differences were observed between two nitrogen fertilizer levels under the same irrigation rates. However, the water use efficiency（WUE） was higher under less-sufficient irrigation than under sufficient irrigation. In conclusion, Irrigation of 900 m3·hm-2 with 30 kg N·hm-2 would be optimum for winter wheat growth and grain quality. |
