冬小麦水分耗散特性与农业节水

本文根据中国科学院禹城综合试验站１９８６年－１９９６年蒸渗仪农田水分模拟试验资料统计；冬小麦全生育期耗水量可达４８２．５ｍｍ，缺水率可达６９．３％；冬小麦全生育不分耗散过程有两个明显的需水峰区和３个关键需水期，为实施节水灌溉提供了实验依据；冬小麦耗水量与环境因子有明显的相关关系，其统计规律可供地下水浅埋区区域灌溉预测参照应用。

ON THE WATER CONSUMPTION CHARACTERISTICS OF WINTER WHEAT AND WATER SAVING IN AGRICULTURE

The total output of winter wheat in Huang Huai Hai Plain in 1993 accounted for 44 4 per cent of that of the whole state and 47 2 per cent of total grain crop of this region. Therefore, it is important to stady the water consumption characteristics of winter wheat. According to the experimental data measured by the lysimeters in Yucheng Experimental Station, CAS, the average water consumption is 482 5 mm for winter wheat and 854 8 mm for both winter wheat and summer maize, for which the rainfall can provide 30 7 per cent and 65 3 per cent respectively in Yucheng Region. Two obvious peaks and three key water demand periods exist in the whole water consumption process of winter wheat and it is possible to make full use of these periods for the irrigation, e.g., the winter, the jointing, the heading or the milking period. The measuremants by the lysimeters, the Bowen ratio meter, the evaporation pans and other pieces of equipment indicate the existence of linear relationships between the daily water consumption of winter wheat and the environmental factors, such as net radiation, soil heat flux, the infrared temperature, the evaporation from water surface and the growing period in days after planting. Two good relationships have been found, one between the cumulated daily water consumption of winter wheat and the growing period in days after planting, and the other between the daily water consumption and net radiation, the infrared temperature of crop canopy and the evaporation from water surface. The above results may be used to estimate the regional crop water consumption and the regional irrigation forecast for the area with similar natural conditions.