- Pick up a marble-sized hunk of moist soil and roll it between your thumb, forefinger and middle finger, as if trying to shape it into a little ball.
- With a clayey soil, your rolling will be successful: youll end up with a ball the size of a marble.
- With a sandy soil, your attempt at forming a ball will be completely unsuccessful: it will fall apart.
- With a loamy soil, your attempt will show some promise, but ultimately fail: the ball will fall apart once you leave off applying pressure.
So what do you do to improve a sandy or clayey soil? The problem with clayey soil is that water doesn't percolate quickly enough through it. Sandy soil, meanwhile, poses just the opposite problem. It may be counter-intuitive, then, but the fact is that you can improve both types of soils by mixing in compost. Compost loosens up clay sufficiently to allow water to percolate through faster, while it retains enough water to counteract the "sieve effect" that plagues sandy soils.