Phytoavailable phosphorus (P2O5) and potassium (K2O) in topsoil for apple orchards and vineyards, South Tyrol, Italy

Accurate fertilization management is a present-day challenge and can conciliate profitability and sustainability in agriculture production. This study presents topsoil concentrations of P2O5 and K2O in apple orchards and vineyards in South Tyrol, Italy. Sixteen thousand georeferenced soil samples were collected and spatialized using ordinary local kriging. Measured average and maximum concentrations of P2O5 were 260 and 1500 mg/kg, respectively, in apple orchards, and 280 and 880 mg/kg, respectively, in vineyards. Similarly, measured average and maximum concentrations of K2O were 210 and 1040 mg/kg, respectively, in apple orchards, and 250 and 820 mg/kg, respectively, in vineyards. Overall, K2O concentration was mostly within the recommended thresholds, while P2O5 concentration was frequently higher than the target level for optimal production. The resulting maps (1:25,000 scale) of P2O5 and K2O showed modest accuracy with RMSE of 115.7 and 78.3 mg/kg, respectively. These maps can support evidence-based decision making by multiple stakeholders.