Originally Posted by Richard
This is the benefit of mulching. Complex carbon acids are leached out with watering and percolate downward. They interact with the clay and slowly cause it to disassociate. The process can be speed up by applying humic and/or fulvic acid before mulching. These are simply concentrate forms of carbon acid complexes.
The common retail moisture meters can give you false readings in clay or partially clay soils. Basically, the clay will cause a reading of "wet" until the clay is completely dry. Otherwise, the meters work well in commercial potting soils.
Where can I get humic or fulvic acid? Will applying these "burn" the existing plants? If the moisture gauge give false reading in clay soil, what can one do to get accurate reading, aside from actually diging up the clay soil to see it directly (that would be too laborious with all the trees I have ).