> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/introduction-1/basin-1/parameters.bsn/p_perc.md).

# p\_perc

Phosphorus percolation coefficient

The phosphorus percolation coefficient is the ratio of the solution phosphorus concentration in the top 10 mm of soil to the concentration of phosphorus in the percolate.
