What describes the amount of soil moisture held after excess water has drained away and the rate of downward movement has decreased?

What describes the amount of soil moisture held after excess water has drained away and the rate of downward movement has decreased?

• A. Wilting point
• B. Porosity
• C. Field capacity
• D. Saturated hydraulic conductivity

Answer: (C)

Field capacity is the amount of soil moisture left after excess water has drained away and the downward movement has slowed. When soil is saturated, gravity quickly drains the freely moving water from the larger pores. What remains is water held in the smaller pores by capillary forces and some adsorption to soil particles. This moisture level represents the upper limit of water the soil can hold under gravity-driven drainage and is the baseline for how much water is potentially available to plants (until the wilting point is reached). The other terms refer to different properties: porosity is the total pore space, saturated hydraulic conductivity is how fast water moves through fully saturated soil, and the wilting point is the lower moisture level at which plants can no longer extract water.

Field capacity is the amount of soil moisture left after excess water has drained away and the downward movement has slowed. When soil is saturated, gravity quickly drains the freely moving water from the larger pores. What remains is water held in the smaller pores by capillary forces and some adsorption to soil particles. This moisture level represents the upper limit of water the soil can hold under gravity-driven drainage and is the baseline for how much water is potentially available to plants (until the wilting point is reached). The other terms refer to different properties: porosity is the total pore space, saturated hydraulic conductivity is how fast water moves through fully saturated soil, and the wilting point is the lower moisture level at which plants can no longer extract water.