不同株型冬小麦冠层结构特征多时相分析

Analysis of winter wheat canopy structure for different plant types of growth period

同一株型不同生育期、不同株型相同生育期其结构参数均具有不同的变化特点,了解其变化,一方面有利于区分不同株型结构,进一步提高LAI(叶面积指数)等指标参数的遥感反演精度,另一方面可用于定量作物肥水管理,提高肥水利用效率。该文结合冬小麦整个生育期,在北京小汤山试验基地开展两期品种试验,对比分析实测冠层多角度光谱及结构参数,得出通过多角度光谱数据区分株型的最佳波段是红光波段,两期LAI与平均叶倾角(ALA)变化均表明,最佳时期为拔节期;起身期至拔节期所选试验品种均体现直立型品种LAI大于披散型品种。2009年试验表明利用J4114月底LAI变化趋势差异也可较好的区分作物株型;披散型品种9428特征尺度变化出现"跷板"效应,可以作为株型识别的依据之一。

It has different characteristics of the structural parameters for the same plant type at different growth stages and the different plant type at the same growth stages.Understanding the changes of parameters can improve the inversion precision of LAI and water use efficiency.In this paper,varieties investigations had been made by multi-temporal and bidirectional canopy reflected spectrum and structural parameters in Xiaotangshan Town,Beijing City.The growth changes of multi-angle spectrum and parameters were analyzed.The results showed that bidirectional canopy reflected spectrum had significant differences on the red band for the different varieties,and the best identification period was the jointing stage.The LAI of erective varieties was larger than the loose varieties between setting and jointing stage of the selected varieties.It also showed that it was feasible to identify plant type based on LAI which had the phenomenon of double peaks（at the end of April） from the experiment of 2009.Characteristic scale has the ＇seesaw＇ effect for the loose varieties 9428 which is one of the bases for the identification of plant structural types.