摘要
【目的】探试利用光谱分析手段估测果树微量元素含量的精度与应用潜力。【方法】首先对果树鲜叶的光谱反射率(Rλ)以及叶片铁(Fe)、锰(Mn)、铜(Cu)、锌(Zn)4种元素含量进行测定,并分别对各种元素含量与Rλ及其多种变式数据(1/Rλl、g(1/Rλ)、d1Rλ、d2Rλ、d1[lg(1/Rλ)]、d2[lg(1/Rλ)]l、g(1/BNC)、f′(Rλ)、Dn)的相关性进行了分析,找出了与每种元素含量相关性最强的光谱数据形式。最后采用逐步回归法,分别对每种元素含量及与其相关性最强的光谱变式数据进行了回归分析,得到了入选波长,并利用入选的波长Rλ进行了基于最小误差平方和的偏最小二乘回归建模。【结果】叶片Fe、Mn、Cu、Zn含量与Rλ的相关性均较弱,但分别与四点差分的一阶微分光谱f′(Rλ)及波长间隔设为17,25和15 nm的d1Rλ的相关性最强;用入选波长Rλ建立的估测模型均具有较好的线性趋势,R2均在0.8以上。【结论】利用光谱分析手段估测果树叶片Fe、Mn、Cu、Zn元素含量的精度较高,具有一定的应用潜力。
[Objective] The research was to evaluate the possibility and application potential of the method of spectral analysis on predicting trace elements of fruit trees. [Method] Firstly, the spectral reflectance (Rλ) and the Fe, Mn,Cu, Zn contents of fresh leaves were measured, and the statistical correlation was analyzed between each element content and Rλ as well as its several transformations (1/Rλl、g(1/Rλ)、d1Rλ、d2Rλ、d1[lg(1/Rλ)]、d2[lg(1/Rλ)]l、g(1/BNC)、f′(Rλ)、Dn) within the wavelength range from 400 nm to 900 nm by factor analysis method, and the spectral reflectance variant, which has the highest absolute value of the correlation coefficient with each of the element's content, was found. Subsequently, the regression analysis was done to each element content and the corresponding spectral reflectance variant of the highest correlation coefficient through the stepwise regression method,and the eigenvalue wavelengths was chosen to carry on partial least squares regression modeling based on the least error square sum. [Result] The results showed that the correlation between the Fe,Mn,Cu,Zn content with Rλ was rather weak and the correlation coefficient was the highest between Fe content and the first derivative of 4 points difference of spectral reflectance f' (Rλ), or between Mn content and the first derivative of spectral reflectance with derivative gap = 17 nm d^1Rλ ,or between Cu content and the first derivative of spectral reflectance with derivative gap = 25 nm d^1Rλ ,or between Zn content and the first derivative of spectral reflectance with derivative gap = 15 nm d^1Rλ . The result also indicated that the regression models established using the wavelengths selected when Sig(it's a probability numerical higher than F detection value) was set to 0.01 and Ramoval to 0.02 had better linear trend, and Re values were above 0. 8. [Conclusion] As a whole, the method of spectral analysis has some applications potential to determine trace elements of fruit trees .
出处
《西北农林科技大学学报(自然科学版)》
CSCD
北大核心
2008年第11期143-150,共8页
Journal of Northwest A&F University(Natural Science Edition)
基金
国家自然科学基金项目(30571527)
关键词
光谱分析
果叶叶片
微量元素
spectral analysis
fruit tree leaf
trace element
作者简介
邢东兴(1969-),男,陕西礼泉人,在读博士,主要从事土地资源与空间信息技术研究。E—mail:pah72@sohu.com
[通讯作者]常庆瑞(1959-),男,陕西子洲人,教授,博士生导师,主要从事土地资源与空间信息研究。E-mail:changqr@nwsuaf.edu.cn