What are the different soil moisture constants used to describe the relationship between water and soil?

✅Explanation:
The relationship between water and soil is described using several key soil moisture constants, each representing a specific moisture condition that impacts soil water availability to plants. These constants help define the soil's capacity to retain and release water at different levels of moisture.
-Field capacity: This is the moisture content of the soil after it has been saturated and allowed to drain freely under the influence of gravity. It represents the amount of water the soil can hold against gravitational forces and is available for plant use.
-Wilting point: This is the moisture level at which plants can no longer extract water from the soil. When soil moisture reaches the wilting point, plants begin to wilt because the water is held too tightly for their roots to absorb.
-Hygroscopic coefficient: This refers to the moisture content of the soil at the point where water is bound tightly to soil particles and is no longer available to plants. It represents the residual moisture in the soil after all available water has been lost to evaporation.