Abstract: The influence of main cultivated practice including different nitrogen application rate, population density, leaf ages of seedling at transplanting, and water regimes on rice canopy spectral reflectance was investigated. Results showed that increasing nitrogen rate, and population density, transplanting young seedling, and flooding irrigation could increase reflectance at near infrared bands and decrease reflectance at visible bands. Using reflectance of green, red and near infrared bands and ratio index of 810 nm to 560 nm could distinguish the different types of rice under different cultivated practice by fuzzy cluster analysis.

Key words: rice, cultivated practice, canopy reflectance spectrum, fuzzy cluster analysis, elongating stage

摘要： 分析了不同栽培措施（密度、移栽叶龄、施氮量及水分管理方式）对稻田拔节期冠层反射光谱的影响，并对其进行了模糊聚类分析。研究表明，不同栽培措施通过影响水稻拔节期群体生长特征而引起冠层反射光谱发生变化。增施氮肥、水层灌溉、减小栽插秧龄和增加密度都使近红外波段反射率增加，可见光波段反射率降低。用绿（560 nm）、红(660 nm)和近红外（810 nm）3个波段的反射率和比值植被指数为指标，用模糊聚类方法可以完全无误地区分开拔节期不同处理的水稻群体。说明通过光谱分析可以识别不同栽培措施和生长状况下的水稻群体。

关键词: 水稻, 栽培措施, 冠层反射光谱, 模糊聚类分析, 拔节期