不同氮肥水平与毛竹林反射光谱的关系

Effects of different fertilizer supplies on reflectance spectrum in leaves of Phyllostachys pubescens

为了探讨施肥量与毛竹叶片反射光谱特性和色素含量的关系,对不同氮肥水平下毛竹叶片色素含量及反射光谱参数进行了测试,并分析了光谱参数红边位置与色素含量的相关性。结果表明:施用氮肥能够显著提高毛竹叶片的色素含量。在施氮肥250kg/hm2时,叶绿素a、叶绿素b和类胡萝卜素的含量比对照分别提高了19.9%、31.7%和14.0%;显著降低叶片可见光区525～605nm波长的光谱反射率,并且使红边位置向长波方向移动。毛竹叶片叶绿素a、叶绿素b和类胡萝卜素与红边参数之间均存在极显著相关性。利用光谱红边参数可以更加快速、准确地对毛竹叶片叶绿素含量进行估测,并筛选适宜施肥量。

To evaluate the relationship among reflectance spectra characteristics,pigment contents and fertilizer supplies,we tested the pigment contents and reflectance spectra index in the leaves of Phyllostachys pubescens under different fertilizer supplies,and analysed the correlation between red-edge parameters and pigment content.Results showed that the pigment contents in leaves of P.pubescens increased significantly under fertilizer supplies（urea）,the chlorophyll a,chlorophyll b,and carotenoids content increased by 19.9%,31.7%,and 14.0% than control under 250 kg/hm2 fertilizer supplies.The spectral reflectance decreased significantly in the visible region from 525 to 605 nm,while red-edge position shifted to longer wave lengths.There were significant relationships between red-edge parameters and chlorophyll a,chlorophyll b and carotenoids content.It is suggested that reflectance spectral index,especially red-edge parameters could be used for monitoring pigment content of P.pubescens as well as choosing the optimum fertilizer supplies more quickly than traditional methods.