Soil structure cannot be changed easily. However, the addition of organic matter and working the soil at the proper moisture level improve soil structure. Correct soil moisture level exists when soil crumbles easily when turned over with a fork or spade. Soil should not stick to the fork or spade. Working wet soil compacts structure and reduces air and water spaces.
Water is a solvent for vital plant nutrients.
The presence and movement of water through the soil affect the availability of these nutrients to the plant. Water will drain quickly across a sloped surface. This is called surface drainage. Additionally, there is internal drainage. Gravity moves water vertically through the soil.