摘要
以不同氮素供应水平下的水培生菜为研究对象,采用光谱仪和叶绿素仪分别获得生菜叶片的漫反射光谱信息和叶绿素含量,通过提取生菜叶片光谱的红边参数,分析不同氮素供应水平下红边参数的变化规律,以及各个红边参数与生菜叶片叶绿素含量间的关系。结果表明,随氮营养供应水平的提高,生菜叶片各红边参数呈现不同的响应趋势。红边位置、最小振幅、红边面积以及红边振幅和最小振幅比值与生菜叶片SPAD值间均具有极显著的相关关系,其中以红边位置的相关程度最高,其相关系数为0.9420,均方根误差为1.803。可见,红边位置可以作为生菜叶片氮素营养诊断的一种有效指标。
In order to obtain the optimum red edge parameters for using rapid detection of the lettuce leaf nitrogen content,the response feature of red edge parameters for leaf spectra under different nitrogen levels and the relationship between red edge parameters and leaf nitrogen contents were investigated.Visible and near infrared（Vis-NIR） spectroradiometer was used to collect the leaves＇ spectral data of water culture lettuce,and the chlorophyll meter（SPAD 502） was used to measure the leaf chlorophyll content.Red edge parameters,which included red edge position（λred）,red edge area（Sred）,red edge differential（Dλred）,the minimum of red edge differential（Dλmin） and the ratio of Dλred to Dλmin（Dλred/Dλmin）,were calculated based on the first derivative reflectance spectra in the red edge region.The results showed that the dynamic characteristics of red edge parameters changed with different nitrogen nutrition levels in water culture.It was concluded that λred,Dλmin,Sred and Dλred/Dλmin had significant relationship with the leaf chlorophyll content,respectively.In all red edge parameters,the correlation degree of λred was the highest with correlation coefficient 0.9420.And the root mean squared error was the lowest with 1.803.Therefore,it was demonstrated that λred could be a predictor for lettuce leaf nitrogen content.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2011年第11期174-177,共4页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家高技术研究发展计划(863计划)资助项目(2008AA10Z204)
江苏省农业装备与智能化高技术研究重点实验室项目(BM2009703)
江苏大学高级人才启动项目(06JDG065)
江苏高校优势学科建设工程资助项目(苏财教(2011)8号)
关键词
生菜
氮素
红边参数
可见-近红外光谱
Lettuce
Nitrogen
Red edge parameters
Visible-near infrared spectroscopy
