While ADA As came in 5th, it was under a much more controlled set up, zero nutrients in the flow through water column.
The water was also harder.
In practice, the EI(or EI lean, does not matter really) + ADA As combo is nice and provides better growth attributes that most hobbyists like, and it's more consistent and less mess than lake mud.
Lake mud will have more and a wider range of nutrients, which is important in a controlled limited enviroment.
In our tanks, we can add K+, traces etc, PO4 etc, some comes from our dosing and some comes from fish etc.
Having nutrients in both locations, even in the sediment experiment, we'd expect to find higher/highest rates of growth where non limiting nutrients exist in both places.
While some plant species does well with pure water column, others might not.
Adding both locations seems wisest, then the plants have ample nutrients both locations and if you mess up the water column dosing here and there, it's not as critical.
I freely admit ADA AS +EI is better than EI and inert sand alone.
But both work well and can be done to a higher level.
But EI+ADA AS is easier to do and allows wider ranges of dosing routines to the water column. ADA also looks nice and works easier for most than mud.
Nothing wrong with mud though.
It might be more complete but needs labor to clean it and the amounts of N and P etc are not always known etc, ADA should be fairly standard and does not muck the tank up nor require a 2 part layer like soil.mud.
Regards,
Tom Barr