Dualex植物多酚叶绿素仪在冬小麦氮素状况无损诊断中的应用
摘要
准确估计和及时诊断作物氮素状况有助于季节施肥管理。为了评估三个叶片和冠层光学传感器在无损诊断冬小麦氮素状况方面的性能，使用七个小麦品种和多种氮素处理（0–360 kg N ha−1）进行了三个试验，于2015年至2018年在中国江苏省进行。在主要生长期，分别使用两个叶片传感器（SPAD 502，Dualex 4 Scientific+）和一个冠层传感器（RapidSCAN CS-45）获取叶片和冠层光谱数据。同时测定了叶片氮浓度（LNC）、叶片氮积累（LNA）、植株氮浓度（PNC）、植株氮积累（PNA）和氮素营养指数（NNI）五个氮素指标。在每个生长阶段，建立了六个基于传感器的指数（叶片水平：SPAD、Chl、Flav、NBI、冠层水平：NDRE、NDVI）与五个N参数之间的关系。结果表明，基于Dualex的NBI在四个叶传感器指标中表现相对较好，而RS传感器的NDRE在不同生长阶段的五个N指标估计中，由于冠层传感器的采样面积较大，因此表现最好。NNI诊断模型的面积一致性范围为SPAD为0.54至0.71，NBI为0.66至0.84，NDRE为0.72至0.86，SPAD为0.30至0.52，NBI为0.42至0.72，NDRE为0.53至0.75。总的来说，这些结果揭示了基于传感器的诊断模型在快速、无损诊断N状态方面的潜力。
关键词：氮指示剂；氮营养诊断；光学传感器；光谱指数
Evaluation of Three Portable Optical Sensors for Non-Destructive Diagnosis of Nitrogen Status in Winter Wheat
Abstract
The accurate estimation and timely diagnosis of crop nitrogen (N) status can facilitate in-season fertilizer management. In order to evaluate the performance of three leaf and canopy optical sensors in non-destructively diagnosing winter wheat N status, three experiments using seven wheat cultivars and multi-N-treatments (0–360 kg N ha−1) were conducted in the Jiangsu province of China from 2015 to 2018. Two leaf sensors (SPAD 502, Dualex 4 Scientific+) and one canopy sensor (RapidSCAN CS-45) were used to obtain leaf and canopy spectral data, respectively, during the main growth period. Five N indicators (leaf N concentration (LNC), leaf N accumulation (LNA), plant N concentration (PNC), plant N accumulation (PNA), and N nutrition index (NNI)) were measured synchronously. The relationships between the six sensor-based indices (leaf level: SPAD, Chl, Flav, NBI, canopy level: NDRE, NDVI) and five N parameters were established at each growth stages. The results showed that the Dualex-based NBI performed relatively well among four leaf-sensor indices, while NDRE of RS sensor achieved a best performance due to larger sampling area of canopy sensor for five N indicators estimation across different growth stages. The areal agreement of the NNI diagnosis models ranged from 0.54 to 0.71 for SPAD, 0.66 to 0.84 for NBI, and 0.72 to 0.86 for NDRE, and the kappa coefficient ranged from 0.30 to 0.52 for SPAD, 0.42 to 0.72 for NBI, and 0.53 to 0.75 for NDRE across all growth stages. Overall, these results reveal the potential of sensor-based diagnosis models for the rapid and non-destructive diagnosis of N status.
Keywords: nitrogen indicator; nitrogen nutrition diagnosis; optical sensor; spectral index
