玉米冠层叶片光谱反射率与玉米长势空间变异的关系  

Spatial variability and relationship of spectral reflectance and growth status to corn canopy

作　　者：李树强[1,2] 李民赞[1] 李修华[1] 赵瑞娇[1] 张彦娥[1] 

机构地区：[1]中国农业大学现代精细农业系统集成研究教育部重点实验室,北京100083 [2]河南科技大学车辆与动力工程学院,洛阳471003

出　　处：《农业工程学报》2011年第12期110-114,共5页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(U0931001);高等学校博士学科点专项科研基金(20100008110030)

摘　　要：为了寻找一种快捷获取玉米叶绿素空间分布信息的方法,研究了玉米苗期冠层叶片光谱反射率的变化特征,分析了不同生长阶段冠层叶片光谱反射率的空间分布和叶绿素质量浓度的空间分布。研究结果表明:玉米苗期冠层叶片叶绿素的质量浓度空间分布不均匀。冠层叶片的叶绿素质量浓度与光谱指数RVI的相关性较低,与归一化差异植被指数NDVI值和550nm波段的反射率均有较高的相关性。分析550nm波段的反射率值与冠层叶片叶绿素质量浓度值的相关关系,显示二者成负相关变化趋势,相关系数绝对值在0.69～0.88范围随着生长期的变化而逐渐增大,五叶期前期的相关性系数绝对值达到苗期最大值,表明550nm波段反射率值能够较好的反映玉米苗期叶绿素质量浓度的水平,分析和掌握550nm波段反射率值的变化及其空间分布特性对快速监测玉米苗期生长状况,对指导田间施肥具有重要意义。In order to find out a convenient way of acquiring chlorophyll spatial distribution, the canopy spectral reflectance of corn seedlings was measured. The spatial distribution of canopy spectral reflectance and the chlorophyll content were analyzed on different growth stages. The results indicated that the spatial variability of the canopy chlorophyll content of corn was unstable at different growth stages. The variance was kept in a higher level over the growth stages. The correlation coefficients between chlorophyll content of corn canopy leaf and each vegetation index, NDVI, RVI, and spectral reflectance of 550 nm, were calculated. The chlorophyll content showed better correlation with NDVI and reflectance of 550 nm, while there was no high correlation between chlorophyll content and RVI. Focus on the relationship between reflectance of 550 nm and chlorophyll content, it was found that the correlation coefficient varied among -0.88^-0.69, and the highest value was observed at the early period of the five-leaf stage. It showed that the reflectance at 550 nm might characterize the chlorophyll content of corn canopy leaves. The method can be used to support the precision fertilization during the growth stages of corn.

关 键 词：光谱分析 叶绿素 GPS 精准施肥 玉米冠层 苗期 

分 类 号：S126[农业科学—农业基础科学]