Evaluation of Near Infrared Spectroscopy (NIRS) for Estimating Soil Organic Matter and Phosphorus in Mediterranean Montado Ecosystem

The Montado is an agro-silvo-pastoral ecosystem characteristic of the Mediterranean region. Pasture productivity and, consequently, possibilities for intensifying livestock production depend on soil fertility. Soil organic matter (SOM) and phosphorus (P2O5) are two indicators evolution fertility in this ecosystem. However, their conventional analytical determination by reference laboratory methods costly, time consuming, laborious thus, does not meet needs current systems. aim study was to evaluate alternative approach estimate SOM P2O5 based near infrared spectroscopy (NIRS) combined with multivariate data analysis. For purpose, 242 topsoil samples were collected 2019 eleven fields. These subjected analysis NIRS NIRS, 165 used during calibration phase 77 external validation phase. results showed significant correlation between models quantification these parameters. coefficient (R2, 0.85 0.76 P2O5) residual predictive deviation (RPD, 2.7 2.2 obtained indicated potential P2O5, which can facilitate farm managers’ decision making terms dynamic management animal grazing differential fertilizer application.