SOIL TESTING KITS - A PASS OR A FAIL?
Recently we (as we usually do) soil pH tested a clients site soil.
pH is defined as ‘potential for hydrogen’ and in this instance measures how acid or alkaline the soil is.
The soil pH on this property was important because the site soil was extremely poor and would require a certain amount of cultivation and minor blending with an imported garden soil prior to the top layer of garden soil being put into place.
If we know the pH of our two soil components we can work out the overall pH of them blended together and know whether or not they need modifying to make them suitable (from a pH point of view) for growing plants in.
When we tested this particular soil it returned an undesirably high alkaline reading, somewhere around pH 8+.
I say ‘somewhere’ because we used an inexpensive off the shelf soil pH testing kit marketed by Manutec.
With these tests you prepare the soil sample by mixing a small portion with a few drops of the indicator liquid and then you dust the sample with the white barium powder provided.
You then measure off the supplied chart to match the colour the subsequent chemical reaction causes the barium to turn to get your pH.
But how accurate?
We arranged for the local field representative of Rocky Point, who was in the area, to swing by and he kindly tested the pH with much more elaborate scientific instrumentation.
His pH reading was 8.2
So it’s fair to say the accuracy of the Manutec soil testing kit is actually pretty good and although it won’t give you a precise reading these kinds of inexpensive soil testing kits will do the job quite satisfactorily for most of us most of the time.
So yes, that would be a ‘pass’.