What is the definition of "field capacity" in soil science?

Field capacity is defined as the amount of water that soil can retain after excess water has drained away, but before permanent wilting occurs in plants. This condition represents the balance between gravitational and capillary forces in the soil, allowing for optimal water availability for plants. At field capacity, the larger soil pores (macropores) are drained of water, while the smaller pores (micropores) remain filled with water, making it accessible for plant uptake.

This is crucial for understanding soil moisture management because it indicates the point at which plants can effectively absorb water, and it helps inform irrigation practices. Maintaining soil moisture at or around field capacity supports healthy plant growth while minimizing problems such as waterlogging or drought stress.