North American Fruit Explorers mailing list at ibiblio

["Lon J. Rombough" <lonrom@hevanet.com>]

Title: Re: [NAFEX] Re: Submission

There is another way to look at this.   In forestry research they have found that mycorrhizal fungi on mineral soils will create areas of low pH (acid) that dissolve and make the minerals available.  Since the fungi also need good amounts of organic matter to grow (such as would be found on a forest floor anyway), it may simply be a matter of the pine forest floor being mineral (sand, perhaps) and the fungi is making organic acids to release the minerals in the soil.   The test would be to clear an area and test the soil in the open after a few years.  Just using pine needles as mulch wouldn't make the soil acid because the right species of fungi to cause that don't grow in garden conditions.
    On the other hand, some plants apparently DO make the soil acid.  In the UK, vast heather barrens exist where there were once forests and the layers of dead material they lay down  make the soil too acid for anything else to grow there.  The Scottish government found that they could cut deep trenches in the soil in the barrens and pines planted there, below the acid layer, would grow and develop into new forests, shading out the heather in the process.  
-Lon Rombough
    
>

> About the pH of pine needles, etc., I'd suggest that maybe it is a phenomenon that is present where pine trees are the predominate tree. I rarely get soil approaching neutral. Practically everyone mulches with pine needles here and the soil is acidic, regardless of what you mulch with. I have to add lime to just about everything that doesn't grow here naturally.
> Doc Lisenby
> Zone 7/8 (pine country)