8 May 2019 - Biofilm in a bed of crushed rock

Attleboro, Massachusetts

When I first came across the concept of remineralization - that is, enhancing the soils and ecosystems by introducing crushed rock, otherwise known as rock dust - I was a little skeptical of one common claim put forth by the proponents of the concept. The claim was that rock dust offers a massive boost to soil bacteria and makes soils qualitatively more fertile by offering numerous chemical elements to be adsorbed into the soil off the surface of rock particles.

But I decided to give this idea a try - if for no other reason than just for the exercise that you get from crushing rock. What you see above is a bucket full of crushed rock I had produced. Naturally, with bits of soil and grass debris that accidentally got in, too - so this is not a very well staged experiment.

The little puddle in the bucket is covered with a thick biofilm. The road is a good 10 meters away, so car exhaust is unlikely to be a factor. Hence more likely than not the biofilm you see is evidence of flourishing microbial life in the bucket.

I must also note that I had added rock dust to some of the potted plants as well as outdoor patches and the plants there seem to be doing better than before. But that was done in conjunction with introducing worms and worm castings to those environments too so it is hard to tell what role, if any, the rock dust had played in the improvement that I believe had taken place.

Related reading

Remineralize the Earth