An Estimation of the Leaf Nitrogen Content of Apple Tree Canopies Based on Multispectral Unmanned Aerial Vehicle Imagery and Machine Learning Methods.

Bibliographic Details
Title: An Estimation of the Leaf Nitrogen Content of Apple Tree Canopies Based on Multispectral Unmanned Aerial Vehicle Imagery and Machine Learning Methods.
Authors: Zhao, Xin1,2 (AUTHOR) 15730999979@163.com, Zhao, Zeyi1,2 (AUTHOR) zeyizhao@aliyun.com, Zhao, Fengnian1,2 (AUTHOR) zfn19990411@163.com, Liu, Jiangfan1,2 (AUTHOR) jiangfangliu@aliyun.com, Li, Zhaoyang1,2 (AUTHOR) lizhaoyang2i1@163.com, Wang, Xingpeng1,2,3 (AUTHOR) 13999068354@163.com, Gao, Yang3,4 (AUTHOR) 13999068354@163.com
Source: Agronomy. Mar2024, Vol. 14 Issue 3, p552. 18p.
Subject Terms: *FRUIT trees, *PARTIAL least squares regression, *MACHINE learning, *NITROGEN fertilizers, *ORCHARD management, *MULTISPECTRAL imaging
Geographic Terms: XINJIANG Uygur Zizhiqu (China)
Abstract: Accurate nitrogen fertilizer management determines the yield and quality of fruit trees, but there is a lack of multispectral UAV-based nitrogen fertilizer monitoring technology for orchards. Therefore, in this study, a field experiment was conducted by UAV to acquire multispectral images of an apple orchard with dwarf stocks and dense planting in southern Xinjiang and to estimate the nitrogen content of canopy leaves of apple trees by using three machine learning methods. The three inversion methods were partial least squares regression (PLSR), ridge regression (RR), and random forest regression (RFR). The results showed that the RF model could significantly improve the accuracy of estimating the leaf nitrogen content of the apple tree canopy, and the validation set of the four periods of apple trees ranged from 0.670 to 0.797 for R2, 0.838 mg L−1 to 4.403 mg L−1 for RMSE, and 1.74 to 2.222 for RPD, among which the RF model of the pre-fruit expansion stage of the 2023 season had the highest accuracy. This paper shows that the apple tree leaf nitrogen content estimation model based on multispectral UAV images constructed by using the RF machine learning method can timely and accurately diagnose the growth condition of apple trees, provide technical support for precise nitrogen fertilizer management in orchards, and provide a certain scientific basis for tree crop growth. [ABSTRACT FROM AUTHOR]
Copyright of Agronomy is the property of MDPI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Academic Search Complete
More Details
ISSN:20734395
DOI:10.3390/agronomy14030552
Published in:Agronomy
Language:English