The content of N, P and K in sugarcane leaves at seedling stage, tillering stage and elongation stage were detected rapidly by visible - near infrared spectrophotometer. A total of 123 leaf sample s' spectra were collected during the three growth periods. After the outliers were detected, 117 valid samples were obtained and spectral data of all samples were preprocessed. Using the spectral data processed by CARS-PCA as an independent variable, a 6-fold cross-validated PLS model for N, P, and K content was established. The R2 of the CARS-PCA-PLS model for N, P, K prediction were 0.8591, 0.6769, and 0.9321, respectively. Correlation analysis of the predicted N, P, and K contents were further implemented to explore the interaction effect between NPK. To simulate the interaction effect between those three major nutrients, 19 factors include possible linear, quadratic, cubic relations between NPK were assumed, multi-factor cubic polynomial regression PLS and MLR correction models were established from those factors. In the modified MLR model, the determinants of N, P and K were respectively 0.8908, 08019 and 0.9139, which improved the performance of the model by 3.7%, 18.5% and 1.3% compared with the CARS-PCA-PLS model which only based on the spectral reflectance data. The results show that the application of visible-near-infrared spectrum combined with interaction effects can effectively predict the content of N, P and K in the sugarcane growing stage. It provides important guiding significance for rapid real-time monitoring of sugarcane growth and fertility management.
|Original language||English (US)|
|State||Published - 2018|
|Event||ASABE 2018 Annual International Meeting - Detroit, United States|
Duration: Jul 29 2018 → Aug 1 2018
|Conference||ASABE 2018 Annual International Meeting|
|Period||7/29/18 → 8/1/18|
Bibliographical noteFunding Information:
This work was supported by National Natural Science Foundation of China (31760342, 31401290, 31360291) and Guangxi Natural Science Foundation (2015GXNSFBA139261), China. The authors are grateful to Mengling Nong, Fusheng Li for their helps in field management and data collection.
© 2018 American Society of Agricultural and Biological Engineers. All rights reserved.
- Interaction effect
- Sugarcane Leaves
- Visible -NIR Spectroscopy