Healthy soil contains a network of spaces as well as particles of different sizes. Tiny spa allow fr air a flowing wa to re living ro while lar animals cre connected chan through dee layers during movement. Heavy pressure can compress these spaces, making the soil harder for roots to penetrate. The surface may look unchanged even when its internal structure has been altered. Gardeners therefore try to avoid repeatedly walking on growing beds. Protecting the spaces between particles can be as important as adding material to the ground.

Type only the missing letters. Each box is one letter, and the number of boxes matches the letters that are missing.