Monitoring leaf nitrogen in almond orchards using airborne hyperspectral and Sentinel-2 imagery

An accurate assessment of leaf nitrogen (N) status is essential for developing sustainable agricultural management strategies and implementing precision agriculture practices. Through imaging spectrometers installed onboard drones, aircraft, or satellite platforms, remote sensing techniques can prov...

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Detalles Bibliográficos
Autores: Wang, Yue, Suárez, Lola, Poblete, Tomás, Hornero, Alberto, González-Dugo, Victoria, Ryu, Dongryeol, Zarco-Tejada, Pablo J.
Tipo de recurso: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/393738
Acceso en línea:http://hdl.handle.net/10261/393738
https://api.elsevier.com/content/abstract/scopus_id/85195651504
Access Level:acceso abierto
Palabra clave:Chlorophyll fluorescence
Plant traits
Radiative transfer model (RTM)
solar-induced chlorophyll fluorescence (SIF)
Descripción
Sumario:An accurate assessment of leaf nitrogen (N) status is essential for developing sustainable agricultural management strategies and implementing precision agriculture practices. Through imaging spectrometers installed onboard drones, aircraft, or satellite platforms, remote sensing techniques can provide accurate, timely, and spatially explicit information on leaf nutrient status. However, even though leaf chlorophyll-sensitive and structural vegetation indices have been traditionally used as valuable plant nutrient indicators, their sensitivity to leaf N may be limited when assessing dense and well-fertilized canopies. New methods based on hyperspectral remote sensing can provide physiological indicators for explaining leaf N variability based on physiological traits. The present study demonstrates that chlorophyll a+b content derived from radiative transfer models presents superior performance for mapping leaf N variability in comparison with standard vegetation indices used in precision agriculture of almond orchards. Furthermore, this study illustrates the feasibility of using Sentinel-2 imagery to explain leaf N content, despite the coarser resolution compared to airborne imagery. Based on model-retrieved plant traits (e.g., Cab, Cw, Cdm) obtained from Sentinel-2, this study evaluated the performance in estimating leaf nitrogen concentration. Results showed a reasonable level of reliability, yielding r<sup>2</sup>=0.79 in 2020 and r<sup>2</sup>=0.72 in 2021.