Analysis of water consumption and yield characteristic of aerobic rice in North China

Two years field experiment (2001 ~ 2002) was conducted in Beijing to explore the effect of irrigation on yield, yield component, water use efficiency (WUE) and water consumption characteristics of two aerobic rice cultivars (“HD297”and “HD502”). When irrigation is 300～522 mm, yield of “HD297”and “HD502” is 3 876～5 289 kg·hm^－2 and 3 977～5 664 kg·hm^－2 respectively and corresponding WUE is 1.01~ 1.29 g·kg^－1 and 1.03～1.33 g·kg^－1. Significant differences exist among irrigation treatments; however, yield and WUE of “HD502” are always higher than those of “HD297” for all treatments. Therefore,“HD502” is more suitable for Beijing area than “HD297”. The analysis on aerobic rice yield shows that WUE increases by 1.9%～27.7% with only 7.9%～29.8% decrease in yield, especially in early and middle stages, the highest increase of WUE, 3.6%～23.1% increase with only 7.9%～15.5% decrease in yield, is observed in limited irrigation treatment. Therefore limited irrigation in early stage and sufficient irrigation in later stage is the best water-saving irrigation model for aerobic rice in Beijing. Using historical weather data for Beijing, precipitation characteristics for the growing season of aerobic rice are analyzed. The period is divided into three phases based on precipitation in the growing season of aerobic rice and using the Person-III method. The relation between water requirement of aerobic rice and precipitation is discussed. It is necessary to irrigate at all growth stages of aerobic rice in mild and dry years. However, irrigation is only needed at flowering to maturity stage in humid years.