Building a healthy organic soil

[Hermitian]

Originally Posted by Redbaron

1) Depends what you mean. As potting soil? Nope, that would take years. As soil additive in the ground? Absolutely it will be made available to the plants. It is a process called mineralization. Basically you are right. Unavailable to plants, but it is available to certain forms of bacteria, which then get eaten by protozoa and other soil animal life like worms and then that waste is consumed by fungus, which is also consumed by those protozoa, worms etc.... The real question is do you have enough life in the soil to make available these minerals for the plants? If you have a very active biology in the soil, those minerals from rock dust and seaweed will be available to the plants. In fact, plants can even signal certain beneficial bacteria and fungus what they need specifically, and have the microbiology go get it for them.

The material in question (rock from gravel quarries) is not decomposed by bacteria in any significant quantity on a timeline of years or decades. If you want to talk about decomposition from acid, then yes it can occur but your plants would be dead from the acid concentration.

For other types of rock minerals, yes mineralization is possible in many cases.