Target nutrient concentrations
- The following data, from various sources, provide guidance on required concentrations of nutrients in soil.
- Always use the PRG models to calculate requirements of N, P and K fertilisers.
- Availability of nutrients may be influenced by soil moisture, root growth and interactions with nutrients, clay, organic matter, etc, in soil.
- Use tissue samples to check actual availability of nutrients.
Nutrient concentrations and indices
- Concentrations of available nutrients are measured by standard soil tests as mg / litre.
- Concentrations may also be expressed according to the Defra Index scale.
Potash Development Association (2011) Leaflet 24.