中文摘要：

以2007-2009年连续2个冬小麦生长季的田间试验数据为基础，利用GreenSeeker获取冠层归一化差值植被指数（NDVI），分别对不同氮营养条件下冬小麦的产量变化、冠层NDVI值随施氮量和生育期的动态变化，以及NDVI与产量的相关性定量分析，建立基于NDVI的冬小麦产量估算模型。结果表明，冬小麦的产量变化随施氮量的增加呈抛物线趋势变化；冠层NDVI在返青期前随施氮量增加基本不变，返青期至灌浆初期随施氮量增加呈显著增加趋势；整个生育期冠层NDVI呈现“低-高-低”变化趋势。冬小麦整个生育期不同施氮水平下的NDVI值与产量的相关性均为正相关关系，且相关性随生育期逐渐增强，在灌浆末期达到最大。利用NDVI建立的冬小麦产量估算模型，以灌浆初期（P=0．005）和灌浆末期（P〈0．C01）的模型达到极显著水平。经验证，灌浆初期的冬小麦产量预测值与实测值的回归关系达到了显著水平（P=0．0129），灌浆末期则达到极显著水平（P=0．0002）。因此，利用灌浆初期和灌浆末期的NDVI值可以预测冬小麦产量，尤以灌浆末期预测效果更佳。

英文摘要：

The field experiment was carried out in two winter wheat growing seasons during 2007-2009. Winter wheat canopy re- flectances in the 656 nm and 770 nm wavelengths were obtained by GreenSeeker at over-wintering stage, reviving stage, jointing stage, early-filling stage, and last-filling stage, respectively, in order to compute NDVI [（N1R770-R6s6）/（N1R770＋R656）]. Yields were collected at harvest stage and compared anlong different nitrogen application rates. Canopy NDVI changes were analyzed with ni- trogen increasing and growth, respectively. Furthermore, correlation analysis was done between yield and canopy NDVI. Yield esti- mation models were established for winter wheat based on canopy NDVI. Results showed that, winter wheat yield changed in parab- ola shape with N increasing. Wheat canopy NDVI value presented almost changeless before reviving stage, but great increase from reviving stage to early-filling stage with N increasing. In the whole growth stage, canopy NDVI value presented a trend of ＂low-high-low＂. The correlation between canopy NDVI and yield was positive in the whole growth stage with different N rates and gradually became higher with growth, and up to the highest at the late-filling stage. The yield estimation models based on canopy NDVI at early-filling stage （P=0.005） and late-filling stage （P〈0.001） were greatly significant. Regression validated between pre- dicted and measured values was significant at early-filling stage （P=0.0129） and greatly significant at late-fiUing stage （P=0.0002）. Therefore, it is feasible that using canopy NDVI at early-filling stage and late-filling stage estimates winter wheat yield, especially at late-filling stage.