Belaid et al. (2026) Bridging canopy light interception and absorption: Toward a multi-scale radiometric framework for precision irrigation in woody crops

Identification

• Journal: Science of Remote Sensing
• Year: 2026
• Date: 2026-09-08
• Authors: Mohamed Ibrahim Belaid, Jaume Casadesús
• DOI: 10.1016/j.srs.2026.100505

Research Groups

• Institute of Research in Agrifood and Technology (IRTA)
• Universitat de Lleida Agrotecnio-CERCA Center

Short Summary

This review critically examines the theoretical foundations, methodological developments, and irrigation applications of Canopy Light Interception in woody crops over the past three decades. It synthesizes empirical formulations, geometric approaches, radiative transfer modelling, and advances in proximal and remote sensing to provide a comprehensive understanding of light interception in orchard systems.

Objective

• To clarify the conceptual boundary between fIPAR and fAPAR for translating canopy radiation assessments into decision-support tools for water-efficient orchard management under increasing climatic pressure.
• To examine the relationship between intercepted and absorbed radiation, particularly in discontinuous orchard systems where structural heterogeneity may challenge relationships established for more homogeneous vegetation.

Study Configuration

• Spatial Scale: From individual leaves to entire orchards, with a focus on row-structured canopies and pronounced spatial heterogeneity.
• Temporal Scale: Diurnal, daily, seasonal, and multi-year variations in light interception, including effects of sun position, cloud cover, leaf movement, canopy development, pruning, and tree phenology.

Methodology and Data

• Models used:
  • Empirical and semi-empirical models (Beer–Lambert law)
  • Radiative transfer modelling (RTMs) with three-dimensional canopy representations
  • Geometric and shadow-based approaches (shadow fraction models and gap fraction models)
• Data sources: Ground-based measurements, proximal sensing (e.g., hemispherical photography), remote sensing (e.g., satellite-derived products), and airborne imagery.

Main Results

• The conditions under which fIPAR approximates fAPAR are examined, revealing that their divergence is more relevant in discontinuous orchard systems than in homogeneous canopies.
• RTMs enable the direct computation of fIPAR by resolving photon interactions with foliage under both direct and diffuse radiation.
• Geometric and shadow-based approaches provide computationally efficient alternatives for estimating light interception in structured orchard systems.

Contributions

• This review provides a comprehensive synthesis of canopy light interception assessment in modern fruit orchards, emphasizing advances in measurement and assessment through ground-based, proximal, remote sensing, and modelling approaches.
• It highlights the relevance of fIPAR to water use efficiency and irrigation scheduling, especially within precision agriculture for woody crops.

Funding

• Not specified.

Citation

@article{Belaid2026Bridging,
  author = {Belaid, Mohamed Ibrahim and Casadesús, Jaume},
  title = {Bridging canopy light interception and absorption: Toward a multi-scale radiometric framework for precision irrigation in woody crops},
  journal = {Science of Remote Sensing},
  year = {2026},
  doi = {10.1016/j.srs.2026.100505},
  url = {https://doi.org/10.1016/j.srs.2026.100505}
}