ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa
CURRENT PROBLEMS IN REMOTE SENSING OF THE EARTH FROM SPACE

  

Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2026, V. 23, No. 4, pp. 282-292

Predicting wheat crops nutrient status using multispectral and hyperspectral remote sensing data, machine learning and spatial cross-validation

A.A. Struev 1 , E.P. Mitrofanov 1 , V.P. Yakushev 1 , V.M. Bure 1, 2 , O.A. Mitrofanova 1 
1 Saint Petersburg State University, Saint Petersburg, Russia
2 Agrophysical Research Institute, Saint Petersburg, Россия
Accepted: 16.07.2026
DOI: 10.21046/2070-7401-2026-23-4-282-292
Traditional methods for diagnosing the supply of plants with macro- and micronutrients are labor-intensive, expensive, and do not allow obtaining continuous spatial maps. The development of remote sensing technologies opens new opportunities for operational crop monitoring; however, for many elements that lack characteristic absorption bands in the visible and near-infrared ranges, the problem remains unsolved. Moreover, many existing studies use random cross-validation, ignoring spatial autocorrelation, which leads to overestimation of model accuracy. In this work, a reproducible machine learning approach is developed and validated for predicting the concentrations of 12 macro- and micronutrients in the aboveground biomass of spring wheat using multispectral (5 bands) and hyperspectral (300 bands, 390–1031 nm) data. A feature set was constructed comprising 44 broadband vegetation indices, window-based statistics, and textural descriptors characterizing the spatial heterogeneity of the canopy. For model evaluation, buffered leave-one-out cross-validation was applied, accounting for individual spatial autocorrelation radii. The approach employed mRMR feature selection, Bayesian hyperparameter optimization, and ensemble machine learning methods. It was found that under correct spatial validation all 12 nutrients in the multispectral pipeline yield positive coefficients of determination R2 in the range of 0.11–0.46. A physical separation of signal sources was revealed: for macronutrients (N, S, Ca), vegetation indices played the leading role (50–55 % importance), whereas for micronutrients and cobalt, textural features dominated (62–100 %). Comparison with the hyperspectral data showed that, despite 53–80 % of predictive information lying outside the multispectral range, at equal sample size the multispectral pipeline with texture channel outperforms the hyperspectral one without textures for 11 out of 12 elements, especially for cobalt and nitrates. Random cross-validation overestimates R2 by 0.13 on average, confirming the necessity of spatially-correct evaluation. The developed approach is promising for constructing nutrient distribution maps (especially for nitrogen, phosphorus, and potassium) suitable for variable rate fertilization, as well as for future development of hyperspectral orthomosaics, integration of textures with hyperspectral spectra, cross field validation, and use of the SWIR range for micronutrients.
Keywords: remote sensing, multispectral imagery, hyperspectral imagery, vegetation indices, textural features, machine learning, spatial cross-validation, micronutrients, spring wheat, precision agriculture
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