Effects of vegetation, terrain and soil layer depth on eight soil chemical properties and soil fertility based on hybrid methods at urban forest scale in a typical loess hilly region of China - Fig 7

Spatial distribution maps for the soil comprehensive fertility index (F) integrated based on eight soil chemical properties in the three soil layers predicted using the high accuracy spatial interpolation method: (a) 0–20 cm soil layer, (b) 20–40 cm soil layer, and (c) 40–60 cm soil layer.