> 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/databases/plants.plt/untitled-19.md).

# nfix\_co

The nitrogen fixation coefficient in the SWAT+ plant database is 0.5 for legumes and 0.0 for non-legumes.