The pH scale and soil testing.

The pH scale.

The pH scale measures how acidic (or how alkaline) a substance is. Most of the substances which you handle in the lab have pH values between t and 14. A substance with pH 1 is very acidic. A substance with pH 14 is very alkaline. A substance with pH7 is neutral.

Soil testing.

When the smart family arrived at their new home, Fred looked at the garden, thought of his father, and shuddered. The garden was huge. His father was a gardening fanatic who did everything just as the book said. That meant lots of work for Fred!

It didn't take long for the first gardening job to come along. The very next morning, Mr. Smart was reading his gardening book in the section 'New Gardens'. 'To grow fruit and vegetables successfully', it said, the soil pH must be correct. Each plant will grow best at a particular pH. Before planting anything in a new garden, make sure that you test the Soil.’ And so, that afternoon, Fred found himself out in the garden with a soil testing kit in one hand and a trowel in the other.

What Fred did? Fred tested soil from different parts of the garden, following the kit's instructions.

These said:

1 Take several small samples of soil from different parts of the

Plot.

2 Dry the soil, then mix it.

3 Shake some soil with indicator,

4 Match the indicator colour to the pH chart.

what he found out. Fred drew a plan of the garden and put his results on it. He shaded each plot with the indicator colour given in the test and left his father to work out what his results meant.