Water In Soil
Water is one of the most important ingredients in any soil. Without water, soil formation would not be possible.
Water enters soil via a number of different processes. The most common is through precipitation, such as rain and snow. This precipitation enters the soil and drains down into it.
In many cases, water also enters soil from the dirt beneath it, as water climbs upward to fill the empty spaces between particles of dirt.
Many substances dissolve into water, and are carried from one portion of the soil to another. Water makes chemical reactions in the soil possible, and supplies micro-organisms with the water necessary for life.
Water leaves soil via evaporation, as well as through drainage. Excessive water can rob soils of their nutrients by carrying them away to other locations. This process is known as leaching.
The maximum amount of water that a soil can handle is known as the soil’s field capacity. When a soil is at field capacity, it means that all available pores in the soil are already filled with water, and that there is no room for more water to enter.
In temperate areas, where four seasons are experienced, it is not uncommon for soils to reach field capacity during the winter, when low temperatures inhibit plants from using water and also decreases evaporation.
Conversely, during the summer the opposite can take place. Plants require great amounts of water to survive, causing their roots to drain the soil’s water supply. Increased evaporation also decreases water levels, creating a deficit, where the soil has less water than it needs to support the lifeforms living within it. When this happens, plants begin to wilt, and animals begin to die.