[NAFEX] nafex pH Question

list at ginda.us list at ginda.us
Sat May 5 09:09:47 EDT 2007

On May 4, 2007, at 8:18 PM, oowonbs at netscape.net wrote:

>> I don't know a lot on the topic and I don't know what pH southern  
>> soil
> normally is. But my statement only address the fact that what comes
> into the
> tree is the same as what eventually falls off.
> Kurt
> Hmmm, so a lemon tree out west... ;>)

I'm no expert on the pH of plants, but I'm pretty sure that it's not  
true that "what comes into the tree is the same as what falls off",  
at least, not if you are also assuming that what's in the soil is the  
same as what comes into the tree.  Trees and other plants burn energy  
and are active living things that control their pH as well as other  
aspects of their internal chemistry.  Yes, it takes engery to drive  
the pH differently, but plants are good at gathering and using  
energy.  Similarly, healthy people can eat food that's somewhat  
acidic or somewhat basic, but we maintain our internal pH within very  
narrow boundaries.  Most life forms can do that.

And of course, most plants have a preferred range of pH for the soil  
they grow in, so it's certainly possible that all blueberry leaves  
are acid because blueberries have a lot of extra H+ to work with, and  
dump some of it in their leaves.  (just an example, I have no idea  
what the pH of blueberry leaves is)

Plants differentially take up elemental nutrients from the soil,  
too.  The only "nutrient" for which I've seen numbers is lead, and  
for lead, I know that some plants take up vastly more than others  
from the same soil, so much so that there are some crops that can be  
grown to remediate lead-heavy soil.  Although, in that case, I wonder  
what you're supposed to do with the lead-heavy leaves those crops  

In the discussion a couple years ago about pine needles,

On Oct 22, 2003, at 9:20 AM, Jim F wrote:
>      Why do so many people believe the 'old wives tale' that pine  
> needles and oak leaves make the soil acidic?
>      Upon the first day of my Horticulture class, for a gee-whiz  
> experiment, I grind up dry pine needles, add distilled water,  
> insert a pH meter, and ask a student to read the meter.  "Oh, it's  
> alkyline," is the usual response.  Not very alkyline, really, with  
> a pH of 7.2 to 7.3.  Next, I take a jar of pine needles and oak  
> leaves that have been fermenting for a month and ask another  
> student to read the meter.  "pH 7.0," is the invariable response.   
> For the last portion of the experiment, I have a third student read  
> the pH meter for a jar of pine needles and oakleaves that have been  
> composting in my garden for a year.  The pH is still 7.0, no more  
> acidic than other composted vegetative matter.
>      Every time I encounter a conifer that I hadn't tested before,  
> I collect its needles for a pH test and I have yet to discover  
> acidity among those I have tested.  Perhaps there is a species of  
> conifer, somewhere, whose needles make soil acidic, and if there  
> is, I just haven't found it yet.
> Jim Fruth
> Pequot Lakes, MN


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