trailanimal
son of soil
once again, the key is a thriving communityThose numbers look fairly accurate. They do not exist in a lab though. The majority of that iron is not plant available. It is dependent on pH, bacterial action, OM content, depth, temperature... etc. Same for most nutrients, there is moreP in soils than every plant in the world together could use in hundreds of years, but only a tiny fraction is in plant available form.