Development of Nitrogen Parameter Detector for Orchard Monitoring Based on Spectroscopy

Abstract

In order to monitor nitrogen content of the jujube tree in the orchard, a spectroscopy-based nitrogen parameter detector was developed. It was designed with one control unit and several measuring sensor nodes. The sensor nodes were used to measure the canopy reflectance of jujube tree plant. Each sensor node contained four optical channels to measure the sunlight and canopy radiation at the wavebands of 550, 650, 766 and 850 nm respectively. The control unit was applied to receive, display and store all the data sent from several sensor nodes. The data was transferred based on ZigBee wireless network. The transmission quality between the sensors and control unit was evaluated. The result showed that the signals could be transmitted precisely without packet loss when the distance was less than 100 m. The calibration experiment indicated that the minimum correlation coefficient between illuminometer and each light channel of the sensors was 0.917. The NDVI (650, 766) was calculated from the developed sensor and used to monitor the nitrogen content of jujube tree in the orchard with r² = 0.638. It provides a new method to monitor the nitrogen parameter in the orchard non-destructively.

Keywords::

• Optical sensor
• ZigBee
• NDVI
• Nitrogen content
• Orchard monitoring

Additional information

Notes on contributors

Lixuan Wu

Lixuan Wu, Master's student in China Agricultural University. His research focuses on sensor development using wireless sensor network technology. The sensors were developed for crop monitoring in greenhouse and field. Email: [email protected]

Hong Sun

Hong SUN, Ph.D., assistant professor in the China Agricultural University. Her research focuses on agriculture intelligent detection using spectral technology and image processing. The research topics include vegetation growth monitor and revegetation status detection. Tel: [phone]; Email: [email protected]

Minzan Li

Minzan Li, Ph.D, professor in China Agricultural University. He received the Ph.D. degree in Tokyo University of Agriculture and Technology (Japan). His research focuses on precision agriculture, especially on spectral analysis and application. The research topics include crop growth status monitor, soil nutrition detection and the sensor development. His works has been published including 9 patents and over 70 refereed conference and journal papers. He is a member of the Chinese Society of Agricultural Engineering. Tel: [phone]; Email: [email protected]

Yao Wen

Yao Wen, Master's student in China Agricultural University. Her research focuses on crop detection using spectral technology. Tel: [phone]; Email: [email protected]

Yi Zhao

Yi Zhao, Master's student in China Agricultural University. His research focuses on sensor development in precision agriculture. The optical sensor and control system were developed for crop monitoring. Tel: [phone]; Email: [email protected]