1. Prediction of Soil Potassium Concentration Using Electrical Impedance Spectroscopy

The increasing global dependence on potassium fertilizers and instabilities in international trade, intensified by recent geopolitical conflicts, have raised concerns regarding potassium (K) availability and costs in 2026. Since variable-rate fertilizer application enables the optimization of agricultural inputs, the delineation of management zones based on the spatial variability of soil potassium concentration becomes essential. This study aimed to evaluate the use of electrical impedance spectroscopy... I. Salvador, A.L. Coelho, S.V. Valarares, D. Queiroz