Abstract: To investigate the water demand characteristics of oat in North and Northeast China, the water requirement, moisture loss index, and coupled rainfall degree of early sowing oat (April to July) and late sowing oat (May to August) throughout the whole growing period from 1960 to 2014 were estimated by using SIMETAW model. The results indicated that average water requirement of late sowing oat was less than that of early sowing oat, but average effective rainfall was greater than that of early sowing oat. There were differences in spatial distribution characteristics of water requirement, and the spatial distribution of effective rainfall increased from south to north and from west to east. The moisture loss index of each site was less than 0, showing the effective rainfall of oat during the growth period couldnot meet the water requirement if irrigation is not carried out. The water requirement situations during the growth season of oat did not match the coupled rainfall degree, which caused precipitation to be insufficiently utilized. What’s more, coupled rainfall degree of late sowing oat was greater compared to early sowing oat. Consequently, it was approved to postpone oat date of seeding in time under appropriate soil and climate conditions, which was helpful to make full use of precipitation and reduce irrigation. The results provided reference for rational utilization of water and scientific planting of oat in study areas.

Key words: oat, sowing date, water requirement, moisture loss index, coupled rainfall degree

摘要： 为探究华北和东北地区燕麦需水特征，采用SIMETAW模型对1960—2014年早播燕麦（4—7月）和晚播燕麦（5—8月）生育期需水量、水分盈亏指数及降水耦合度进行了分析。结果表明：研究区域晚播燕麦生育期平均需水量小于早播燕麦，有效降水量大于早播燕麦，导致缺水量较小。早播和晚播燕麦生育期需水量空间分布不同，而有效降水量呈现由北向南、由东向西递减的空间特点。各站点燕麦水分盈亏指数均小于0，在没有灌溉条件的基础上，生育期降水量均不能满足燕麦的需水要求。燕麦生长阶段需水情况与降水耦合度不匹配，造成水资源浪费，其中晚播燕麦全生育期降水耦合度较高，对降水的利用程度大于早播燕麦，在土壤墒情允许的条件下，适时推迟燕麦播期可充分利用自然降水而减少灌溉用水。上述结果可为研究区域燕麦的合理用水和科学种植提供参考。

关键词: 燕麦, 播期, 需水量, 水分盈亏指数, 降水耦合度