Failing to correct soil acidity can result in losses to crop yield and quality. The optimum availability of most plant nutrients occurs over a small range of soil pH values (see chart).

Soil pH or soil reaction is an indication of the acidity or alkalinity of soil and is measured in pH units. Soil pH is defined as the negative logarithm of the hydrogen ion concentration. The pH scale ...

Chemical dye kits involve adding a solution to a soil sample and comparing the resulting color to a pH chart. Electronic meters provide a digital pH reading when inserted into the soil.

Likewise, the trees, perennials, and shrubs in the second chart prefer acidic soils. Lower pH in regions with alkaline soils. If you live on the coast or areas that receive lots of rain ...

then comparing the results to a chart. Depending on the type of kit, there may be other steps involved. "Soil pH testing kits ...