Comparing soils from different places
Chemistry · Key Stage 2 · The School
Soil is not all the same
Dig up soil in two different gardens and you can get two very different results. Soil is made of broken-down rock mixed with rotted plants and animals, called organic matter. How much of each, and how big the rock pieces are, decides the type of soil.
Sandy soil
SANDY soil has large, loose grains. Water drains through it fast, so it dries out quickly. It feels gritty and falls apart in your hand. Plants that need less watering, like lavender, often grow well in it.
Clay soil
CLAY soil has very fine, tightly packed grains. Water drains through it slowly, so it can stay soggy and waterlogged after rain. It feels sticky and can be rolled into a ball. Some plants struggle here because their roots cannot get enough air.
Testing two soils side by side
Pour the same amount of water onto a cup of sandy soil and a cup of clay soil, over containers to catch the drips. The sandy soil's water drips through in seconds. The clay soil's water takes minutes, and some sits on top without going in at all. Same water, same amount, very different soil. A gardener who knows this can choose the right plants for the soil they actually have.