Phosphorus (P) is a particularly complex nutrient in the soil because large amounts can be ?locked? up making it unavailable to plants. Measurement of P in soil, and determining fertiliser requirements, are therefore difficult as not all P measured will be available for plant uptake. See Phosphorus factsheet for more detail.
Diffusive Gradient in Thin-Films (DGT) is a new method of measuring soil phosphorus and other micronutrient levels, with tests showing it to be a more accurate measure of the growing crops nutrient requirement than more conventional methods. DGT-P is different to standard measures of soil phosphorus as it reflects the capacity of the soil to supply P in the soil rather than to the concentration of phosphorus in an extract. The DGT-P method aims to ?mimic? the plant root by only measuring the phosphorus in the soil that is accessible to the plant.