中文摘要：

【目的】由适时获得的高光谱数据代替传统繁琐的实验室土壤养分测定数据来进行变量施肥,实现冬小麦高产优质的目标。【方法】本研究利用冬小麦起身期和拔节期冠层光谱数据,选用反映冬小麦长势信息的优化土壤调节植被指数（OSAVI,optimization of soil-adjusted vegetation index）和变量施肥模型进行变量施肥管理（变量区）,以相邻地块常规非变量（均一）施肥区（对照区）为对照,研究了不同氮肥处理冬小麦冠层光谱特征及其施肥效应。【结果】变量施肥之后两种氮肥处理在敏感波段670nm和760～900nm处反射率差异明显,而670nm和760～900nm是氮素和冠层的敏感波段,说明进行变量施肥时,利用基于这两个波段组合的光谱指数OSAVI优于其它波段组合的光谱指数;OSAVI不同生育时期的变化情况,反映了变量施肥在调控作物长势及群体结构上的优势;与对照区相比变量区提高产量达378.72kg·ha^-1,并降低了各小区产量之间的变异,变量区土壤硝态氮浓度降低,氮肥利用率提高,生态效益较为明显。【结论】该技术通过改善冬小麦群体质量,延缓了植株衰老,促进干物质和氮积累,增加冬小麦产量和氮肥利用率。

英文摘要：

　【Objective】The aim of this study was to develop the time-specific and time-critical method to overcome the limitations of traditional field sampling methods for variable rate of fertilization.【Method】Experiments with uniform（CK）and variable rate of nitrogen fertilization were carried out during 2005-2006 on an experimental farm in Beijing（40°10＇N,116°26＇E）.The relationship between the vegetation index（OSAVI,optimization of soil-adjusted vegetation index）and nitrogen content of wheat plant was used to determine the amount of nitrogen fertilizer recommended for variable rate management in precision agriculture.【Result】 There was a big difference for canopy spectral reflectance between the two nitrogen application types in wavebands of 670 nm and 760-900 nm after variable-rate nitrogen fertilization.It was proved that the reliability of using OSAVI was preferable than other wavebands.OSAVI was used to estimate of the influence of variable rate nitrogen fertilization on winter wheat growth condition.Analysis based on the OSAVI variability of different growth states of winter wheat showed that variable rate nitrogen fertilization can improve the growth of wheat.Compared to the CK,the variable-rate nitrogen fertilization reduced the variability of wheat yield and increased wheat yield.It could also prevent under ground water pollution and environmental deterioration.【Conclusion】 The results suggested that accumulation rate of dry matter and N makes wheat yield and N use efficiency increase because of improving wheat population and leaving Senescence after variable rate nitrogen fertilization.