[CH] pH meters

Byron.Bromley (Byron.Bromley@Gsd-Co.Com)
Thu, 25 Mar 1999 09:17:59 -0500 

Harold

I read his statement as It didn't matter, what the pH was.
and that + or -2 was close enough

1 lb of wood ash = 10 lb of lime for soil pH adjustment. One of the
big reasons to own a pH meter. Too many people just throw lime or
wood ash on the garden without measuring first and wind up with
soils so sour you can't grow a thing.. If your soil is somewhere
near the right pH 1 lb of wood ash per 500 sq ft is enough. 
    Been there-done that.

It appears that you and Mr Begg work in a place that supplies these
tools for you. These tools maybe needed for the nth degree of
accuracy for research work, but totally impracticle for the home gardener.
A .01 is not needed for the home gardener, I doubt if 90% on the list
would want to spend the time needed to calibrate the instruments you are
using. I surely don't want to waste the time. On a cheap meter where the 
scales are in 1 point spread I can interpolate + or - 0.1. I can not
interpolate a pH paper within the needed range.

I try to follow an old Eastman Kodak policy K.I.S.S.
Keep It Simple Stupid.
The simpler it is the less likely it is to make stupid mistakes.

There is a reason for the soil pH of 6.75 being ideal, for peppers,
 When the pH gets below 6 the plants cannot absorb
calcium and phosphorus, and above 7 it has trouble absorbing the minor
elements. 

Here is a listing from the data sheet packed with a $20 pH meter

Below a pH of 6 nutrients less available to a plant are
Nitrogen
Phosphorus
Potassium
Calicium
Magnesium

When the soil pH gets above 7 Nutrients less available to the plant
Iron
Manganese
Boron
Copper
ZInc.

One of the big reasons to hold a pH 6.5 for Peppers is that the ability
to use phosphorus drops over 75% between a pH 6.5 and pH 6.0 
The fall off starts at 6.5.
Peppers need a lot of phosphorous.

Personaly I try to hold my soil pH for peppers around 6.75, allows
a little leaching leaway.

Where as your potatoes and Blackberries like a pH of 5.5

Your sand experiment is more proof of why to get more organic stuff
in your soil, and that nutrients leach out of sandy soils more rapidly
than any other soil.

Byron