摘要
在不同施肥方式下研究了长期试验地夏玉米在4个典型生育期的叶绿素相对含量（SPAD）、叶面积指数（LAI）和冠层光谱特征,系统分析了单波段以及由可见光和近红外波段组成的归一化差异植被指数（NDVI）与叶片叶绿素含量和LAI的相关性.结果表明：在同一个生育期,NK、PK处理和CK的光谱曲线特征相似,NPK、NP、OM、1/2OM1/2NPK处理的光谱特征曲线相似.除460nm外,其它单波段反射率与叶绿素含量和LAI都显著相关,尤其在510~1100nm波段相关性最为密切;不同波段组合的NDVI与这2个指标也显著相关,且相关系数大于单波段.从拔节期到乳熟期,绝大部分NDVI都可以有效地拟合叶绿素含量和LAI的变化,选用NDVI（560,950）和NDVI（660,760）建立拟合模型（R2〉0.60）,并以NDVI（560,950）拟合效果最佳（R2〉0.80）.可见,不同施肥方式条件下长期试验地夏玉米冠层光谱特征与叶绿素含量、LAI都具有良好的相关性,可以为夏玉米肥料管理提供科学依据.
Remote sensing is an important and effective technical method to monitor the crop. Long-term experiment reflectance were measured at four typical growth stages of summer maize under different fertilizations. The correlations between the single wavelength,NDVI that visible light and near infrared combined and chlorophyll （SPAD readings）, LAI were analyzed in detail. The results showed that the characteristic curve of canopy spectral of NK and PK were similar to CK＇s,NPK,OM＇s were similar to 1/2OM1/2NPK＇ s. All single wavebands were well correlate with leaf chlorophyll and LAI except 460nm,especially at 5104 1 100 nm. NDVI were also remarkable related to these two agronomical parameters. The correlation coefficients were higher than that of single wavelength reflectance. Selected NDVI （560,950） and NDVI （510, 760） to establish the model to simulate chlorophyll and LAI from jointing to filling stage,R^2〉0. 60,and NDVI（560,950） was the best one since R^2〉0.80. Therefore,there were well correlation between summer maize spectral reflectance and leaf chlorophyll, LAI in long-term experiment under different fertilizations; the spectral reflectance can provide a scientific basis.
出处
《西北植物学报》
CAS
CSCD
北大核心
2008年第7期1461-1467,共7页
Acta Botanica Boreali-Occidentalia Sinica
基金
国家重点基础研究发展计划(973计划)(2005CB121103)资助
