An ideal topsoil, called loam, is soft and crumbly and has roughly ... Surprisingly, compost can improve clay and sandy soils. Topsoil is for growing things. Dirt is for filling, which is why ...

Tunnel shields are built to slice through soft soil, like sand, clay, and silt. They're not strong enough to carve through a mountain of rock. In order to bore into this mountain, you need a ...

Sandy soil is pale coloured and has large particles. These create lots of small air gaps. Water drains through them easily so it usually feels dry. Clay soil is usually sticky and has small particles.