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Near-infrared spectroscopy for rapid and cost-effective nutritional diagnosis of oil palm: An original study

Year: 2026

Type: article

Abstract: Oil palm (Elaeis guineensis Jacq.) is one of the world’s most profitable tropical crops. Profitability of this crop is mainly link to correct management of fertilization generally based on foliar analysis. Conventional chemical analyses remain costly, slow and logistically demanding. Near-infrared (NIR) spectroscopy offers a rapid and cost-effective alternative, yet broad deployment is limited by the difficulty of building calibration models that remain accurate across diverse conditions.This study evaluated the feasibility of developing a generic NIR calibration for predicting major foliar nutrients in oil palm and assessed the usefulness of a spiking strategy to improve model transferability. A dataset of 436 leaf samples collected from 11 sites on three continents was assembled to maximize variability. Partial least squares models were built using raw spectra in the 1250–2530 nm range and evaluated through cross-validation. leave-one-group-out validation and spiking.High calibration performances were obtained for most macronutrients (0.80 < r² < 0.98). However, prediction accuracy dropped substantially when entire fields were excluded from calibration, particularly for nutrients with weaker NIR signatures such as P, K and Ca. Spiking consistently improved prediction ability compared to leave-one-group-out validation, and correcting field-specific biases, while requiring only limited additional laboratory analyses.These results demonstrate that combining a diverse global calibration dataset with targeted spiking provides an efficient and scalable framework for NIR-based foliar nutrient diagnosis in oil palm. With the growing availability of portable NIR devices, this approach has strong potential for on-site, real-time nutrient monitoring in both industrial plantations and smallholder contexts.

Source: Smart Agricultural Technology

DOI: 10.1016/j.atech.2026.102626

Authors: Vrignon-Brenas Sylvain, Avit Valentin, Ollivier Jean, Sarazin Vivien, Flori Albert, Chaix Gilles