What is field capacity in relation to soil?

Field capacity refers to the amount of water that soil can retain after excess water has drained away and the rate of downward movement has significantly decreased, meaning that the effect of gravity on the soil is minimal. This state is particularly important for understanding how much water is available for plant roots to uptake, as it reflects the balance between soil moisture and air space in the soil.

At field capacity, the soil is maximally saturated with water, but it is not waterlogged; the gravitational water has drained away, allowing held water that can be used by plants to be available in the micropores of the soil. This concept is crucial for effective irrigation practices and for managing soil health in agricultural settings.

Understanding field capacity helps in determining the ideal timing and amount of irrigation required to maintain crop health while minimizing water waste. The other options do not pertain to the specific scientific concept of field capacity in soil physics and hydrology, which is focused specifically on water retention after drainage.