What properties or characteristics do all types of soil share?
Soils that are mostly sand drain very well, but do not hold water.
Soils composed mostly of clay do not drain well. This can be a problem because plant roots have a difficult time penetrating clay soils, which can become compacted after heavy rains, as well as hard and clumpy when the soil finally does dry out. The exchange of nutrients and minerals between plant roots and clay soils may be limited. Clay soils are also alkaline (basic). In spite of these factors, clay soils can be good for plants that are not drought-resistant since they do hold water longer.
The best soil for agriculture is a combination of sand, silt, and clay. Silt particles are larger than clay but smaller than sand. They allow for both drainage and water retention, and allow plant roots to grow and spread out. Since there is better aeration among these particles, microbes can more efficiently decompose organic matter into more useful forms.