He Cai-lian, Zheng Shun-lin, Wan Nian-xin, Zhao Ting-ting, Yuan Ji-chao, He Wei, Hu Jian-jun
Guang Pu Xue Yu Guang Pu Fen Xi. 2016 Sep;36(9):2930-6.
In order to know the potatoes nitrogen situation rapidly and accurately, promoting the efficient use of nitrogen fertilizer on the potatoes. Using the feature of portable hyperspectral spectrometer, digital cameras and SPAD-502 chlorophyll meter to abtain the potato digital indicators, leaf spectral and SPAD. Analysing the change status of digital indicators, leaf spectral index, SPAD and production of potatoes under different nitrogen levels in two key periods. Analysing the correlation between canopy image, leaf spectral and SPAD and production, with SPAD as auxiliary validation index, nitrogen fertilizer efficiency evaluation of yield to make sure potato canopy image under the most economic nitrogen application levels and leaf spectral’s critical value to explore the methods of nitrogen nutrition diagnosis quickly and simply. The results show: (1)With nitrogen levels increased, potato tuber formation stage and tuber bulking stage leaf spectral reflectance is the emergence of the "red shift" phenomenon, and the red edge parameters REP, Lwidth, FD_Max increased, Lo decreased. (2)With the nitrogen levels increased, potatoes tuber formation stage and tuber bulking stage digital indicators G/B, (G-B)/(R+G+B) decreased gradually, B/(R+G+B) increased gradually. (3) with the increase of nitrogen application rate SPAD is increased.It is obvious low nitrogen levels increase production with nitrogen increased. It is not obvious the high level of nitrogen stimulation effect. Potato canopy image, leaf spectral and red edge parameters have good correlation with SPAD value and productions, establishing the index evaluation of nitrogen nutrition abundance or lack of quantitative standard of potatoes. Indicating digital image and spectrum technology to nitrogen nutrition diagnosis of potatoes is feasible, provide research ideas and technical support for the potato accurate monitoring of nitrogen nutrition.
为快速、准确了解马铃薯氮素状况，促进马铃薯氮肥高效利用。利用便携式高光谱仪、数码相机和SPAD-502叶绿素仪的特性获取马铃薯数字指标、叶片光谱和SPAD值。分析两个关键时期不同施氮水平下马铃薯数字指标、叶片光谱指数、SPAD值及产量的变化状况。分析冠层图像、叶片光谱和SPAD值与产量之间的相关性，以SPAD值为辅助验证指标，对产量氮肥效率进行评价，确定最经济施氮水平下马铃薯冠层图像及叶片光谱的临界值，探索快速、简便的氮素营养诊断方法。结果表明：（1）随着施氮水平的提高，马铃薯块茎形成期和块茎膨大期叶片光谱反射率出现“红移”现象，红边参数REP、Lwidth、FD_Max增大，Lo减小。（2）随着施氮水平的提高，马铃薯块茎形成期和块茎膨大期数字指标G/B、(G-B)/(R+G+B)逐渐减小，B/(R+G+B)逐渐增大。（3）随着施氮量的增加，SPAD值增大。低氮水平下增施氮肥增产明显，高氮水平下刺激效果不明显。马铃薯冠层图像、叶片光谱及红边参数与SPAD值和产量具有良好的相关性，建立了马铃薯氮素营养丰缺的指标评价定量标准。表明数字图像和光谱技术用于马铃薯氮素营养诊断是可行的，为马铃薯氮素营养精准监测提供了研究思路和技术支撑。
