You'll have to calculate it.

Available (kg/ha) = ppm × soil depth (cm) × bulk density (g/cm³) × 0.1

Soil depth= 20, ppm = your predictions

Gap = Required - Available (in kg/ha)

To calculate nutrient availability and the GAP, you'll definitely need PPM and soil depth data. Have you explored any soil survey databases or local agricultural extensions? Sometimes, you can find that info there. Alternatively, consider soil testing; it's like leveling up in io games, giving you precise stats to optimize your yield!