It would be good if all information regarding variable DMT content were in one place.

So here's all I know. Rain can dissolve DMT out of dead plant material, especially if the water is acidic. Is this valid?

What other factors affect the content?

Not sure if there are generalizable claims to be made or if it depends on species.. Here's some on phalaris:

https://wiki.dmt-nexus.m...act_DMT_From_Phalaris.3F

Check out the festi and samorini publication linked there for in depth information

Here is a link to a study that demonstrates a significant increase of tryptamine content in phalaris grass that is given ammonium sulfate fertilizer.