Vinci et al. (2026) Estimation of Crop Coefficients of a High-Density Hazelnut Orchard Using Traditional Methods vs. UAV-Derived Thermal and Spectral Indices

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Agriculture
• Year: 2026
• Date: 2026-03-17
• Authors: Alessandra Vinci, Raffaella Brigante, Silvia Portarena, Laura Marconi, Simona Lucia Facchin, Daniela Farinelli, Chiara Traini
• DOI: 10.3390/agriculture16060677

Research Groups

Not specified in the provided text.

Short Summary

This study evaluates the use of UAV-derived spectral (NDWI) and thermal (CWSI) indices to estimate crop coefficients ($K_c$) in high-density hazelnut orchards, finding them more accurate than standard FAO56 coefficients.

Objective

• To compare traditional crop coefficient estimation methods (FAO56, transpiration-based, and ground cover reduction) with UAV-derived indices (NDWI and CWSI) to improve irrigation scheduling in high-density hazelnut orchards.

Study Configuration

• Spatial Scale: Local scale (subsurface-drip-irrigated hazelnut orchard, cv. Tonda Francescana®, central Italy) with two planting densities: 625 and 1250 trees $\text{ha}^{-1}$.
• Temporal Scale: 2021–2024.

Methodology and Data

• Models used: FAO56 single crop coefficient, transpiration-based coefficient, and ground cover reduction factors.
• Data sources: UAV-derived multispectral and thermal imagery (for NDWI, CWSI, and canopy geometry), local weather station (for reference evapotranspiration), and recorded irrigation volumes.

Main Results

• The standard FAO56 crop coefficient ($K_c = 0.9$) overestimated evapotranspiration, particularly in the lower planting density (625 trees $\text{ha}^{-1}$).
• Ground cover-based reduction factors and transpiration-based coefficients provided ET estimates more consistent with actual irrigation volumes.
• UAV-derived NDWI and CWSI coefficients yielded mid-season values closely aligned with the transpiration-based method for both planting densities.

Contributions

• Demonstrates that UAV-derived spectral and thermal indices can effectively capture the combined effects of canopy development and water status in high-density hazelnut orchards.
• Provides a flexible, spatially explicit framework for refining crop coefficients to optimize irrigation scheduling in young or high-density tree crop systems.

Funding

Not specified in the provided text.

Citation

@article{Vinci2026Estimation,
  author = {Vinci, Alessandra and Brigante, Raffaella and Portarena, Silvia and Marconi, Laura and Facchin, Simona Lucia and Farinelli, Daniela and Traini, Chiara},
  title = {Estimation of Crop Coefficients of a High-Density Hazelnut Orchard Using Traditional Methods vs. UAV-Derived Thermal and Spectral Indices},
  journal = {Agriculture},
  year = {2026},
  doi = {10.3390/agriculture16060677},
  url = {https://doi.org/10.3390/agriculture16060677}
}