North American Fruit Explorers mailing list at ibiblio

[Ginda Fisher <list@ginda.us>]

On Oct 25, 2009, at 10:04 AM, Jwlehman@aol.com wrote:

In a message dated 10/25/2009 8:02:02 AM Central Daylight Time, list@ginda.us writes:

Someone on this list has measured the pH of pine needles and says they were neutral (or thereabouts).  But they are traditionally used to mulch blueberries.  And lots of people on this list agree that blueberries like copious organic matter (and are less sensitive to pH if the soil is rich enough in organics).

The clay soil around here runs around 6.8. My neighbor has about 10 varieties of high bush blue berries that do very well in it. There is a large pine woods near him. For years he would get fresh and rotted pine needles and spread them around his bushes. Every year he had wonderful crops, his bushes seemingly loving their environment. My attempt of growing high bush blueberries was a miserable failure in the same type soil w/o pine needle mulch.
 
Now I'm going to let more of my ignorance hang out.  I get this feeling that many are of the opinion that neutral mulch is beneficial only as a mulch and doesn't affect pH. I'd like to have input from an expert. What is neutral on the pH scale, 6.0, 6.5? If neutral is say 6.0 and my soil is 6.8 applying neutral mulch would help bring it down, wouldn't it. Being neutral doesn't mean the absence of, rather the center of the range.
Wouldn't it also help bring acid soil pH up?

Jerry _______________________________________________

Neutral pH is 7.0.  6.8 is ever-so-slightly acid.  Yes, neutral is the center of the range, not "no effect". Different substances that measure the same pH can have a different effect when you mix them with the same thing, as pH measures the ratio of positive to negative ions, but some substances have more free (or free-able) ions than others.  Some weak acids (or bases) have a strong "buffering" capacity, meaning they blunt the impact of other acids and bases and tend to maintain a pH close to their own regular pH.  Soil chemistry and pH are very complicated, and pH is at best a rough measure of the type of soil you have and what's likely to grow there.

Ginda

(who is remembering her high school chemistry)