Research station overusing dirt

outdoor house (toilet) and some plants (mealwood, oxyfern) consume a lot of dirt. If you run out of dirt, perhaps it is not only research station which consumes it?

I ran out of dirt fast but then teleported to Eden asteroid and there is plenty of dirt there.

When I replaced the outdoor house with lavatory the dirt consumption was not only significantly reduced but even better was reversed (lavatory produces dirt through compost).

Yeah, I thought about that, and I'm sure that's not it. I'm post-outhouse use, and I've looked at the contents of the research station while it was not in use; it was stocked with more than 50 kg. of dirt, which depleted down to nothing while I looked on. No dupe was researching at the time, and I'm still researching at a crawl, simply because of lack of dirt (or, rather, constantly needing to supply it to the research station). I realize that I have a few plants which also consume dirt, but I still can't make it account for the fast depletion of my stores...