Feng Lei, Hu Xingyue, He Yong, Huang Min, Zhu Zheyan
College of Biosystems Engineering and Food Science, Zhejiang University, 310029, Hangzhou, China (e-mail:
Conf Proc IEEE Eng Med Biol Soc. 2005;2005:3125-8. doi: 10.1109/IEMBS.2005.1617137.
Rapid, non-destructive estimation of nitrogen content of crop is a potentially important application for both farm managers and researchers. This paper presents the development of a multi-spectral nitrogen deficiency sensor, which uses three channels (green, red, near-infrared) of crop images to estimate nitrogen level of the canola. The utility of a Charged Coupled Device Imaging Sensor for rapidly and nondestructively assessing foliar N status of canola was evaluated in two experiments. The sensors assess the nitrogen stress by means of the estimated SPAD value of the canola based on canola canopy reflectance sensed using three channels (green, red, near-infrared) of the multispectral camera. The core of this investigation is the calibration methods between the multi-spectral references and the nitrogen levels in crops measured using a SPAD 502 chlorophyll meter. Based on the results obtained from this study (The correlation was 0.89.), it can be concluded that a multi-spectral CCD camera can provide sufficient information to perform reasonable SPAD values estimation on-the-go during field operations.
快速、无损地估算作物氮含量对农场管理者和研究人员来说都是一个潜在的重要应用。本文介绍了一种多光谱氮素缺乏传感器的开发，该传感器利用作物图像的三个通道（绿色、红色、近红外）来估算油菜的氮水平。在两个实验中评估了电荷耦合器件成像传感器用于快速、无损评估油菜叶片氮素状况的效用。传感器基于使用多光谱相机的三个通道（绿色、红色、近红外）感测到的油菜冠层反射率，通过估算油菜的SPAD值来评估氮胁迫。本研究的核心是多光谱参考值与使用SPAD 502叶绿素仪测量的作物氮水平之间的校准方法。基于本研究获得的结果（相关性为0.89），可以得出结论，多光谱CCD相机能够提供足够的信息，以便在田间作业期间实时进行合理的SPAD值估算。
