1. Evaluation of Diffuse Reflectance Spectroscopy and Machine Learning Methods for Soil Available Phosphorus and Potassium Prediction

Phosphorus (P) and potassium (K) are essential elements for plants. Accurate evaluation of soil available P and K contents is fundamental for precision agriculture and site-specific nutrient management. However, traditional chemical analyses are time-consuming, labor-intensive, and costly. In this context, diffuse reflectance spectroscopy (DRS) has been introduced as a cheaper and rapid alternative; however, its accuracy in estimating soil P and K contents has not been fully proven, particularly... C. Guerra Martins, D.L. Grando, J. Moura Bueno, G. Brunetto, A.A. Kokkonen, L. Peranzoni Deponti, L. Bastos