中文摘要：

作物水源是土壤-植物-大气连续体（SoilPlantAtmosphereContinuum，SPAC）中水分循环及节水农业的重要研究方面。传统方法很难确定不同水源对作物的贡献。本研究通过封丘地区冬小麦田间试验和稳定性氢氧同位素技术，建立了线性混合模型和δD-δ^18O曲线的耦合模型，并采用该耦合模型计算了各水源对各生育期冬小麦的贡献。结果表明：各水源对冬小麦的贡献随着生育期的变化而变化。分蘖、返青和拔节期冬小麦的主要水源为表层土壤水，且对各层土壤水分的利用随着深度的增加而减少；在孕穗期，冬小麦对80cm处土壤水利用最多；开花期80和180cm处土壤水是冬小麦的重要水源；乳熟期40和80cm土壤水分分别贡献了47．5％和39．5％。地下水在孕穗期和开花期对冬小麦的贡献较大，分别为9．0％和16．4％。

英文摘要：

Crop water source is an important aspect in the study on water cycling in SPAC （Soil Plant Atmosphere Continuum） and water-saving agriculture. Traditional approaches are not adequate to determine contributions of different water sources to the crop. Based on the winter wheat field experiment in Fengqiu, using the stable hydrogen and oxygen isotope techniques, a new model coupling a linear mixing model with 8D-8180 curves was established and used to calculate contributions of different water sources to the winter wheat at various growth stages in the Huang-Huai-Hai Plain of China. Results show that contributions of the sources to winter wheat varied with the growth stage. Soil water in the top soil layer （0 - 20 cm） was the main water source to winter wheat at the tillering, regreening, and jointing stages; At the booting stage, the crop got its water mainly from the soil at 80cm in depth; At the flowering stage, it turned to the soil at 80 and 180 cm in depth for water supply; To wheat at the milk stage, soil water at 40 and 80 cm in depth contributed 47.5% and 39.5% , respectively, of the total the crop needed; And at the booting and flowering stages, the crop took 9.0% and 16.4% , respectively, of the water it used up from groundwater.