The soil in which the plant grow can be alkaline, neutral, or acidic. Most plants grow best in soil near neutral pH, but some plants prefer slightly acidic and others slightly alkaline soil. What is the soil pH in your garden? What happens to the pH of water that comes in contact with soil? All the answers are given in this simple project.LETS BEGIN…

What is pH?

pH stands for potential of hydrogen which is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are acidic while the solutions with pH greater than 7 are basic. Pure water is neutral,which is neither acidic nor basic.

Soil pH

Soil pH is considered as a variable in soil which affects many chemical processes. In case of plant, it affect the plant nutrient availability by controlling the chemical forms of the different nutrients.

pH scale

It is the measure of degree of the acidity or basicity of a solution measured on a scale of 0 to 14, called pH scale. The midpoint on the pH scale represents neutral solution having pH 7 which is neither acid nor basic. pH value below 7.0 indicate acidity; numbers greater than 7.0 indicate basicity.pH scale

pH paper

pH papers are infused, saturated (mixture of indicators ) papers which are used to test for alkaline(or basicity) or acidity of substance such as soil. pH papers are thin strips which change color when they come in contact with the material or solution being tested. PH Paper

Testing soil pH using pH paper

Below mentioned are the sequential steps to test the pH of a soil sample using the pH paper:

  1. Take a strip of pH paper.
  2. Gently dip the part of the paper into a soil. Wait for sometime and you will notice the color change in the pH paper strip.pH paper color change
  3. Compare the color obtained on the pH strip with pH chart which have a color-coded scale indicating the pH. pH chart paper


The final output is shown in the figure.From the figure we infer that the soil pH is slightly basic in nature as the color on the pH scale is found out to be 8.pH scale comapre

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Note: It is important to understand that pH is a measure of intensity, and not capacity; i.e., pH indicates the intensity of alkalinity in the same way temperature tells how hot something is, but not how much heat the substance carries.
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