AndyS wrote:
Andy writes:
Hi . I just "discovered" this group and have a question .

I see many versions of soil PH meters for sale from about $20 to $200.

Has anyone used these, do they work well, and are there any good
tips on operating them properly ??

I have a sensor that does not work, I had it exchanged a first time and
the
second one did not work either. The $20 are extremely unreliable. The
litmus
test has shown some consistency by returning the same value of 6.5 on
two tests
of the same dirt. The N, P, K litmus tests from the same kit are not as

consistent, though.

To manage the chemistry of your garden, there is much more to it
than buying a $200 Ph meter. It is money out the window, since after
a few applications of organic matter you will see the pH adjusting to
about 6 to
7 depending on your original soil.

Since you are a retired engineer, let me add that gardening will
test your observational and analytical skills. It is all part of the
fun.

First, you should consider the weeds that are
present around your place. They will tell you a lot about the tilth and
pH.
I have sandy, acid soil (pH between 5 and 5.5) with very little
nutrients in
the native soil. When I amend with wood chips, often it becomes more
acid
and only sheep sorrel will grow there for a while. I can always adjust
with
wood ash (pH 10.4), or leave it alone if I am mulching a tree.
There are weeds, such as chickweed, that will do best in neutral soils,
so you have a chance to check if your garden is OK as well.

Second, you can look at your vegetables. Potatoes don't grow well but,
say, tomatoes
and melons do? It could be around 7. Chard does not grow well, but
collard
does? Probably pH is around 6.0. The best books, like those of Rodale
or Burpee,
will give you an idea of the preferred range for each vegetable, and
also an idea of
nutrient needs. So if the tomatoes grow well you will know there is
enough organic
matter, and if the collards grow well, you will know there is enough
nitrogen.
I have one bed where I group the beets, cabbage, chard, onions all
together,
and spread wood ash generously to get to about 7.0, but the potatoes 10
yds away
never get any ash.

Third, what is the rate of nutrient loss? It is higher with sand, but
it can be quite
low with clay. That will change the pH some, since the pH is closely
related to the
Ca content of the soil. What is the rate of loss through herbivory (you
eating the
veggies)? You will be surprised at the numbers.

Finally, don't forget to install drip irrigation. I did it and it was
part of the funn.


Also, has anyone cross-checked their PH meter with litmus testing to
see if it continues to be reliable even after the sensors grow old ?

Thanks for any discussion on this.

Andy (retired engineer who just planted his first veg
garden)