冬小麦生长期光谱变化特征与叶绿素含量监测研究

在分析冬小麦生长期冠层反射光谱和叶绿素含量变化特征的基础上,对二者之间的相关性进行了研究。表明从小麦拔节期开始,冠层反射光谱在可见光区(400～750 nm)的反射率先降低而后升高,以孕穗期反射率最低;在近红外区(750～1 000 nm)冠层反射率由拔节期至孕穗期反射率降低,然后开始上升。扬花期上升至最高点后又开始下降,直至乳熟期降至最低。冬小麦冠层反射率与叶绿素含量相关分析结果表明,冬小麦拔节期和孕穗期二者呈正相关,扬花期二者呈负相关;整个生长期中,孕穗期可见光区552 nm处反射率与叶绿素含量相关系数最大达0.89。依据冬小麦生长期冠层反射光谱红边拐点位置,分别建立了拔节期叶绿素含量线性检测模型(R~2=0.92)和孕穗期二项式模型(R~2=0.91),用于冬小麦叶绿素含量的无损检测是可行的。

The Spectral Characteristics and Chlorophyll Content at Winter Wheat Growth Stages

The canopy spectral reflectance and chlorophyll content of winter wheat were measured and analyzed in the whole growing season.The characteristics of canopy spectral reflectance indicated that the canopy spectral reflectance changed significantly at different stages.It decreased first and increased later with growth progress in the visible region(400-750 nm) after jointing stage,then the reflectance was lowest at booting stage.In near-infrared region(750-1 000 nm) the spectral reflectance climbed sharply.Th...