水稻反射波谱特征与产量的相关关系

CORRELATION BETWEEN RICE YIELD AND ITS SPECTRAL REFLECTIVE CHARACTERS

用EXOTECH—100BX四通道野外光谱仪,对成都平原的28块水稻样地、5个水稻品种进行多时象的反射波谱测量,两年的研究表明,在水稻的一定生育期间,其反射波谱,特别是红光波段(0.7～0.8μm)和近红外波段(0.8～1.1μm)的反射率与水稻的最终籽粒产量有着密切的关系.水稻的长势越好,则红光反射率越低,近红外反射率越高.本文通过定量分析,分别回归计算了近红外光和红光波段反射率与水稻产量及构成水稻产量的三要素之间的关系.在实际应用中,光谱植被指数RI(或比值植被指数)和NDVI(归一化植被指数)是进行水稻估产较好的参数,它们不仅部分地消除了光谱测量时环境因素对光谱值的影响,而且与水稻产量有着良好的相关性.研究证明,在水稻的黄熟期,RI指数与其产量的正相关关系明显,且越接近黄熟,估产精度越高.

Through a field experiment for two years, it has been found that in certain rice growth Periods there was significant correlation between the yield and the spechal reflectance of red(MSS5)and near infrared (MSS7) spectra. The better the rice growth, the higher the MSS7 and the lower the MSS5. By the regression analysis, several linear lelationships were found between the essential elements of rice yield and MSS7 or MSS7. In fact, the vegetation indices such as RI (MSS7/MSS5) and NDVI CMSS7 - MSS5/MSS7 + MSS5) are much bettet than single spectral channel for monitoring the rice potential yield.These two indices not only could partly eliminate the environmental influence due to measureing spectral data in field, but slso had good correlation with yield.It was verified that there was positive correlation between the RI index and yield during the ripening stage of rice. And the correlati on was improved from r = 0.829(Aug.14) to r=0.966(Aug,22) with the ripening of rice.