This document defines soil and describes its three main types - clay soil, sand soil, and loam soil. Clay soil is made of very fine mineral particles with little organic material. It holds water for long periods but has small particles. Sand soil is generally coarse with small rock particles, retaining few nutrients and having low water holding capacity. Loam soil is a mixture of sand, clay, and silt soils, making it good for planting crops while still holding water well.