油菜叶片的光谱特征与叶绿素含量之间的关系研究

叶绿素是作物生长中的重要因素，是植物营养胁迫、光合作用能力和生长状况的良好指示剂。实时、可靠的作物营养诊断是进行科学施肥管理的基础，也是实践精细农业的关键技术之一。采用便携式可见-近红外光谱仪，在室外自然光照条件下对不同氮肥水平下油菜叶片的光谱特性进行了研究，并根据作物特有的光谱特征，采用逐步回归分析方法建立了油菜叶片的叶绿素含量与红边位置和绿峰位置之间的定量分析模型。结果表明，将红边位置、绿峰位置二者作为自变量时，建立的模型效果优于采用单一的红边位置为自变量时建立的模型效果。其相关系数分别为0.863和0.848；校正标准偏差SEC分别为5.273和5.459, 说明采用红边位置和绿峰位置这两个参数更能很好地预测叶片的叶绿素含量。

Study on the Relationship between Spectral Properties of Oilseed Rape Leaves and Their Chlorophyll Content

Chlorophyll is the important factors of the crop in its growth stage,and it is the favorable indicator of nutrition stress and photosynthesis.Sitespecific crop nutrition diagnosis is the basics of the scientific fertilizer management,and it is essential for the practice of precision agriculture.Spectral properties of the oilseed rape leaves in different nitrogenous fertilizer levels were measured using visible-near infrared reflectance spectroscopy(Vis-NIRS) with natural illumination in the present study.According to the unique spectral properties of the crop,multiple stepwise regression technique was used to find the relationships between chlorophyll content and red edge,green edge.The result shows that the model with two independent variables(red edge,green edge) was better than with the one independeot variable(red edge).The correlation coefficient was 0.863,0.848,and SEC was 5.273,5.459,respectively.It can be seen the combination of the red edge and green edge can accurately predict chlorophyll content.