[gardeners] soil pH

Byron.Bromley (gardeners@globalgarden.com)
Sat, 22 May 1999 09:41:39 -0400

  This spring I purchased from Vesey's seeds a pH meter that looks
looks this one


The range and calibration spec's are the same. I checked my 2 cheapies
against it and could not find a difference

As far as experts go.

On another list a PHD in Micro-Biology and doing plant reseach on Sweet
Potatoes, Used a $1,000 pH meter with temperature compsensating
probes, Calibrated at 4.0 and 8.0 with special calibrating solutions.
Tells me that in one section of his potato field he had a pH of 8.2+
and in another section 2.57+  

I do not profess to be an expert, But those numbers sound like
outside the growing range of most veggie crops that I know of.
Trying to be nice, I will let you draw your own conclusions.

In a cheapie pH meter that I have. It has a nice chart showing
what chemicals are available at what pH level. This chart shows
that above a pH of 7.0 the absorbsion of the five major micro-
elements starts to decline. and below 6.5 Calcium and phosphorus 
levels start to drop.  Below 6.0 Potassium and nitrogen

With the thought that between 6.5 and 7.0 is ideal for most
veggie's, I shoot for 6.75, Which allows leaching either way
for the growing season. Make my major adjustments in the fall
since it takes about 3 months for sulphur or lime to get fully 
worked in.