Feng Lei, Fang Hui, Zhou Wei-Jun, Huang Min, He Yong
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2006 Sep;26(9):1749-52.
Site-specific variable nitrogen application is one of the major precision crop production management operations. Obtaining sufficient crop nitrogen stress information is essential for achieving effective site-specific nitrogen applications. The present paper describes the development of a multi-spectral nitrogen deficiency sensor, which uses three channels (green, red, near-infrared) of crop images to determine the nitrogen level of canola. This sensor assesses the nitrogen stress by means of estimated SPAD value of the canola based on canola canopy reflectance sensed using three channels (green, red, near-infrared) of the multi-spectral 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, it can be concluded that a multi-spectral CCD camera can provide sufficient information to perform reasonable SPAD values estimation during field operations.
特定部位变量施氮是精准作物生产管理的主要操作之一。获取足够的作物氮素胁迫信息对于实现有效的特定部位施氮至关重要。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）来确定油菜的氮素水平。该传感器通过基于多光谱相机三个通道（绿色、红色、近红外）感测的油菜冠层反射率估算油菜的SPAD值来评估氮素胁迫。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素水平之间的校准方法。基于本研究获得的结果，可以得出结论，多光谱CCD相机可以提供足够的信息，以便在田间作业期间进行合理的SPAD值估算。
