摘要
在不同施氮水平夏玉米的6个典型生育期,采用化学方法测定冠层叶绿素含量,利用叶绿素计测定的叶绿素读数以及光谱反射率,系统分析了单波段反射率、可见光和近红外波段组合而成的归一化植被指数（NDVI）、比值植被指数（RVI）等8种常见植被指数与相应时期2种方法测定的叶绿素含量的相关性。结果表明,随着施氮量的增加,叶绿素含量和冠层近红外波段反射率都随之增加;整个生育期中孕穗期在近红外区域反射率最高,与可见光波段反射率相差最大;6个生育期单波段510~1 100 nm反射率、NDVI、RVI等植被指数与叶绿素含量的2种测定结果显著相关或极显著相关,植被指数的表现较单波段更好,且从苗期到乳熟期,各波段反射率与叶绿素的相关性逐渐增强。整体来讲,可见光中560、660 nm和近红外760、810、590和1 300 nm组合的NDVI在各生育期与2个农学指标的相关性较好,选择NDVI（560,760）可以准确拟合夏玉米叶片叶绿素含量,其对化学方法测定的叶绿素含量拟合效果较佳。
Field experiment of different N status were conducted to measure chlorophyll of maize leaves by chemical method and SPAD meter,and canopy spectral reflectance at six typical growth stages of summer maize.The correlation between chlorophyll and the single wavebands,normalized difference vegetation index（NDVI）,ratio vegetation index（RVI） and other vegetation indices combining visible and near infrared wavelength were analyzed,systematically.The results showed that pigments contment of leaves and canopy spectral reflectance in near infrared increased with the increasing of nitrogen rate;there was highest reflectance at booting stage in near infrared and the most difference between visible region and near infrared;there were remarkable correlation between single wavebands from 560 nm to 1 100 nm,and the correlation coefficient of vegetation index were higher than single wavebands reflectance,gradually.On the whole,the ability of NDVI and RVI of wavelength combinations of 560 nm,660 nm in visible light and 760 nm,810 nm,950 nm,1 300 nm in near infrared were better than others.NDVI（560 nm,760 nm） could estimate the content of chlorophyll accuracy.These results indicated that canopy spectral reflectance could be used to non-destructive monitor chlorophyll status in summer maize,and it was better fit the chlorophyll content measured by chemical method than SPAD meter.
出处
《西北农业学报》
CAS
CSCD
北大核心
2010年第4期70-76,共7页
Acta Agriculturae Boreali-occidentalis Sinica
基金
国家重点基础研究发展计划(973计划)(2005CB121103)
关键词
夏玉米
叶绿素含量
特征光谱
单波段
植被指数
Summer maize
Chlorophyll
Characteristic curve of canopy spectral
Single waveband
Vegetation index
作者简介
张俊华（1977-），女，宁夏中卫人，博士，主要从事土壤与环境科学研究。E-mail：zhangjunhua728@163．com
通讯作者：张佳宝。E—mail：jbzhang@issas．ac．cn
