Sand, silt, clay and soil loss

Soil is made of tiny pieces called particles, and their size is a way to name the kind of soil. Sand has the biggest particles. You can see the grains and feel them gritty. Silt has medium particles and feels smooth, like flour. Clay has the smallest particles, so small that they are hard to see. Clay feels sticky when wet and can be moulded. Particle size changes how water moves. The spaces between sand grains are big, so water drains fast. Between clay particles the spaces are tiny, so water drains slowly and the clay stays wet for a long time. Silt is in the middle. Plants need soil that holds some water but also lets air in, so a mix of the three often works well. To test this, a grown-up can make small holes in the bottoms of three cups, fill each with a different soil and pour the same amount of water into each.