Multi-Platform Data Fusion Enhances Nitrogen Management in Citrus Orchards

Researchers from Technion-Israel Institute of Technology have developed a novel approach to estimate canopy nitrogen content in citrus orchards using multispectral and temporal data from unmanned aerial vehicles (UAVs) and Sentinel-2 satellites. This method captures spatiotemporal variability across multiple citrus cultivars, aiming to enhance nitrogen use efficiency (NUE) while reducing environmental impact. The study, funded by the Center for Fertilization and Plant Nutrition, was conducted in commercial citrus plots in the Hefer Valley, Israel, and spanned two phases over three years.

Key Takeaways:

  • The research presents a novel approach to estimate canopy nitrogen content using UAV-satellite data fusion, which captures spatiotemporal variability across multiple citrus cultivars.
  • The integrated Random Forest (RF) model, which combined UAV-VIs, Sentinel-2 VIs, and SfM-derived structural data, achieved superior performance (R² = 0.80, RMSE = 0.17 kg/m²) compared to models relying solely on UAV-VIs or Sentinel-2 VIs.
  • CNC expressed as mass per tree demonstrated a strong positive correlation with yield (R² = 0.66), highlighting the relationship between nitrogen dynamics and orchard productivity.
  • The study provides compelling evidence for the potential of combining UAV and Sentinel-2 data to improve CNC estimation and its correlation with yield in citrus orchards.
  • The research contributes to advancements in precision agriculture by offering a scalable, data-driven framework to enhance nutrient management and support sustainable orchard practices.
  • The study was conducted in commercial citrus plots in the Hefer Valley, Israel, and spanned two phases, with the first phase focusing on four plots of the 'Newhall' cultivar and the second phase expanding to twelve additional plots featuring five different citrus cultivars.

Statistics:

  • Overall, the integrated RF model achieved an R² of 0.80 and an RMSE of 0.17 kg/m².
  • CNC expressed as mass per tree demonstrated a strong positive correlation with yield, with an R² of 0.66.
  • The study used UAV multispectral images and Sentinel-2 satellite images, with a total of six key steps involved in the methodology.
  • The researchers analyzed the relationship between CNC and yield to understand nitrogen dynamics and their impact on productivity.

Sources:

  • NewsRx. Researchers from Technion-Israel Institute of Technology Discuss Research in Sustainable Food and Agriculture (Multi-scale remote sensing for sustainable citrus farming: Predicting canopy nitrogen content using UAV-satellite data fusion). Ecology, Environment & Conservation. August 15, 2025; p 654.
  • Multi-scale remote sensing for sustainable citrus farming: Predicting canopy nitrogen content using UAV-satellite data fusion. Smart Agricultural Technology, 2025,11():100906.