Mr. Phogat,

Via MS.

Maybe electrochemical sensing is an option, with a ladder-type sensor system in the soil and measuring interaction of P with a specific sensor. At least for chloride diffusion in concrete this is a working methodology.

Depending what you need to learn try looking at "DGT' techniques

The diffusion of P in the soil is very slow, so it is necessary to conduct an analysis using the method of soil sampling, taking into account soil parameters and seasonal climate